Winter is Coming: How Do Frogs Avoid Freezing?

Yesterday while shopping at the mall, I noticed that some stores had already begun putting up holiday decorations. The racks were filled with sweaters and down coats. We humans (at least in the northeast U.S.) are preparing for winter. But what about our amphibian friends? How do they prepare for winter? After all, frogs would seem vulnerable to extreme cold with their thin skins and their need to constantly stay moist.

Actually, we don’t need to worry about the frogs. They are well-equipped to deal with the cold weather, even with Arctic temperatures.

Frogs are ectothermic, which means that they rely on their environment to regulate their body temperature. Birds and mammals, including humans, are endotherms. We generate heat chemically and internally by breaking down food. The bodies of ectotherms reflect the air, ground, and water temperatures around them. One advantage that ectotherms have over mammals is that they can survive for long periods without eating.

In the fall, frogs first need to find a place to make their winter home, a living space called a hibernaculum that will protect them from weather extremes and from predators. The frog then “sleeps” away the winter by slowing down its metabolism. When spring arrives, it wakes up and leaves the hibernaculum, immediately ready for mating and eating.

Aquatic frogs and toads such as the leopard frog and American bullfrog usually hibernate underwater in streambeds or on pond bottoms. Because aquatic frogs need oxygen, they lie just above the mud, or only partially buried in the mud, so they are near the oxygen-rich water. They may even occasionally slowly swim around.

Terrestrial frogs and toads typically hibernate on land. Those frogs and toads that are good diggers like the American toads burrow deep into the soil, safely below the frost line. Other frogs, such as the wood frog and the spring peeper, aren’t good diggers and so must scout out their winter homes in deep cracks and crevices in logs or rocks, or they might dig down into the leaf litter.

These frozen peepers and wood frogs might look dead; their hearts have actually stopped beating. But the partially frozen frogs aren’t dead. Instead, they have a kind of natural anti-freeze in their bodies. Ice crystals form in their organs and body cavity, but a high concentration of glucose in the frogs’ vital organs prevents freezing. When spring approaches and its hibernaculum warms up above freezing, a frog’s frozen body will thaw, and it will come back to life.

As you go about preparing for winter, think of the frogs with their amazing adaptations for survival, safe in their winter homes, waiting for spring.

Here’s a video from YouTube about the hibernation of a wood frog. It’s pretty amazing—take a look!

This is a partial repost of an earlier post from December 2010. Most of the information from the post came from an article in Scientific American, How Do Frogs Survive the Winter? by Rick Emmer.

86 thoughts on “Winter is Coming: How Do Frogs Avoid Freezing?

  1. Pingback: Amphibian Rescue and Conservation Project » With Winter Coming, Frogs Play it Cool

  2. I have a small plastic pond. I think it’s 200 gallons. Do I need to put a small pump in it to keep the water oxygenated over the winter. I haven’t put it on all spring and summer, but I’m wondering if I should turn it on for the winter.

  3. I have a couple of green frogs that live on my houseplants, which have been outside all summer. Now that I’ve moved them all inside for the winter, do I need to take the little frogs outside so they can hibernate for the winter? I’m in north georgia, BTW. Thank you!

    • Larry, Yes please take the frogs back outside before it gets too cold. If you don’t then you would need to keep them inside a terrarium and feed them all winter. – Susan

  4. Yesterday I found a frog was living in the toilet in a bathroom I never use.
    I don’t know how long he has been there or what kind he is. I almost wonder
    if he is some escaped pet as he looks strange. Looks almost like some picturs
    of albino frogs except no webbing between the toes, he does have tow pads,
    has a body a little over an inch long and the underside of the rear legs is a
    light golden color. Can I just put him back outside or do I need to keep him inside
    till the weather is warmer. If I keep him inside I sort of need to know what type
    he is so I know what to feed him.

    • Hi Woody,
      We need to know your location and we need to see a picture of the frog, so we can better see what it is. If you are in a cold winter climate, then yes, it must stay with you inside until spring. Please email us more details and a photo to info@frogsaregreen.com. Then we can better help you. – Susan

  5. I didn’t see how to post a picture here so emailed 2 to you . I live
    about 20 miles south of Atlantia Ga. The little fellow has 4 toes
    on the front legs and 5 on the rear with a body excluding legs just
    over an inch long.

    • Woody,
      I received your email and after a consult with an herpetologist, Keith, here’s what he recommends: Gray Tree Frog would be my call. Terrarium wth plants and a small water dish. Room temperature should be good or a bit warmer. Eats small bugs – crickets, mealworms, etc. I emailed you back this info also.
      Thanks, Susan

  6. Hi there, I have frogs that live in my pond. We moved here last June and so this is my first winter. I did a lot of research before clearing my pond before winter came but figured my frogs knew what to do. Today my big one surfaced, but he looks dead. he is bloated and grey. He is just a regular North American type frog, and I was just wondering if there’s a chance he might just not have thawed yet? I put him in the sun, but I would hate to dispose of him if it just that he’s still frozen. I live in Ontario, Canada.

  7. I’ve fallen in love with the tree frogs in my area. I found tree frog habitats that are pvc pipe connected. I don’t want to provide a home that will not be suitable for them to live in during the Winter (I live in NNY). I plan on putting the habitat on the side of my house that has the most shade and is protected from the wind. My gut says sink the pipe below the frost line. Any ideas or other habitat plans out there?
    Thanks!

  8. I live in Ohio & bring my house plants in for the winter. It’s is dec 10, & have just discovered i have a frog of some sort in one of my plants.. I’ve looked all thru the thing, but can not locate the little guy… Is it to late to put it outside for winter & i can’t even see it ? How do i keep it alive till spring ?? Poor thing !!! Help please

    • Hi Brenda,
      I’m sorry for the delay in a response… so busy with the contests that are on right now. I’m going to assume it’s cold outside so it’s too late to take the frog back outside. You should visit a local conservancy or if none are close by, a pet store that has information and supplies for frogs and you can help the little guy through the Winter. Let me know if you need any other help.
      Susan

      • Thank you, for your reply, i just heard it again, but can’t see it, think i will put the plant inside a empty aquarium with some dirt & dish of water till i can get to pet store.. Maybe lore it out & be able to see exactly what i have living with me… Haha, i hope i can help it to survive…

  9. Hi i have a question for you.It may sound ridiculous to you but not to me.Ever since i can remember i have been scared of frogs it is my worse fear ever.Well we moved to a area an there is so many frogs an i dont want to hurt them but i also dont want them at my door step when i come home ,so is there something i can put out side to keep them away …please help

  10. Help! We just found the cutest little gray tree frog on our houseplant. Don’t know how long he’s been there. We live in Chadds Ford, PA, and it is January 8, 2016. We wonder if he can survive winter if we put him outside now. It is 43 degrees now and the next 2 days are going up to 52 and then 61 on Sunday, then way back down to a high of 32, What should we do?

    Please answer asap.

    Thank you.

    • Hi Clara, I suggest you try to take care of it inside. It’s winter and too cold out now to just put it outside and hope it’ll be all right. Let us know if you need further guidance. – Susan

      • Thank you for your response. We have him in a terrarium with the plant he came in on, and we are feeding him a few live crickets each day. Can’t find him now. Might he go into hibernation inside?

        “Further guidance” would be welcome. Our goal is to try to keep him alive until spring and then set him free down near our pond.

        Clara

        • If he’s inside where the temperature is nice, he’ll be fine. I will look through our site for some posts we’ve already written on caring for frogs and send them along. – Susan

  11. I wrote before in January about a little grey tree frog that came in on our houseplant.

    He is doing fine in our terrarium and eating live crickets that we get for him at PetSmart, but I am anxious to let him be free.

    Do I release him down beside our pond when we hear the spring peepers? Should I put him on a tree?

    We live in Chadds Ford, PA so the peepers should probably start in April.

    Thank you,
    Clara

    • Hi Clara,
      It’s always a good idea to release a frog just where you found it. Keep us posted! Make sure the weather is going to stay warm enough before you do.
      Susan

  12. Hi . . I’ve next to a huge nature conservation . It’s mostly all rock with little pockets of trees shrubs plants . I listened to frogs all last winter . During the coldest nights and all. Any ideals . :-O I am not kidding . I know the rock holds heat from the day but even cloudy cold days that night I heard them well into the night. ? Weird and strange I thought. I been trying to figure it out but obviously need help understanding this phenomenon. Thanks

  13. Hello!
    Our spring peepers tree frogs and others in our vernal pools have gone silent after a late spring freeze of 20 degrees. Early in the spring we heard all the chatter and peeps but now all is quiet although temperatures are ideal for mating calls. Will the frogs come back? I can hear others, but far away from our pools. Normally it’s very very loud with a robust population. Plenty of rain, could it be just the late freeze or another factor ( pollution etc?)
    In Milford NH. Thanks!

  14. hi there I have 2 green tree frogs I have them in a tank and a full set up it is winter and I don’t see them much they both go inside a hole in a log I leave live cricket and mealworms but they don’t come out to eat them do they sleep through winter

  15. Hi, my daughter was given two tadpoles from a pet store that received them with their feeder fish. They have no idea what type of frog they will be yet. Currently I have them in our fish tank. When they grow legs I will move them to a separate tank and provide a place for them to have dry land. My question is this, we live in Michigan. How do I care for them in winter? Do I just keep feeding them inside in a tank or will they naturally hibernate in a tank if I keep the tank in our garage or barn.

    • Kathy, If you plan to keep the frogs in a tank you will need to get them a heating pad, even if they were indoors. If in your garage, I’m not sure they will do well there. You should consult with the pet store based on what type of frogs they are. Do not release them outside as they may not be natural to the area. – Susan

  16. Hi, we have had a green frog living in our small pond so summer. We haven’t seen him much the past month or so (we would see him on a daily basis when it was prime mating season), but still hear him call occasionally so know he’s still there. His call seems a lot weaker though, do you think he is just preparing for hibernation? Is there anything we should do to help him through the winter? We live in Indianapolis and our pond has a waterfall and we put in a heater to avoid it freezing in winter. Thanks!

    • Hi Jenny, I’m going to assume the frog has found the spot where he’s going to spend the winter. Please check regularly and let us know if anything changes. – Susan

      • Actually interesting update; we saw a smaller frog than we were seeing all summer; believe it is a young female bull frog. And the next day saw the mall green frog in the pond as well! We had had both a female bull frog and male green frog living in our pond, but unfortunately found the bull frog dead in our basement well :( ! So it was exciting to find another bull frog, hope it sticks around and hibernates through winter in our pond.

        • Hi Jenny,
          Be sure to consult with someone nearby who can see your pond and determine if they can hibernate there. Otherwise you may want to bring them inside for the winter.
          Susan

    • Elaine,
      First, we’ll need to know where you are located? Are you near a pond, assuming that the frog may know when it’s time to hibernate… and move on from your barbeque.
      Susan

  17. A fat green frog moved into my very small pond. I have no heater (can get one) and would like for him to stick around. I’m near portland oregon. I have no clue what he eats. Maybe mosquito larva.do I have to feed him?

    • Dear Lisa,
      Thank you for your email and concern over the frog who has come to visit. Is the pond natural or man-made? Hoe deep does it go? Have you had frogs visit before? Can you take a photo or two of the pond, area and frog and email them so we can have more background on the situation?
      Thanks, Susan

  18. I have a small backyard pond in Lancaster Pennsylvania. My pond is about 36″ across: 24″ x 24″ in the deepest area surrounded by a 12″ shelf that is about 12″ deep. For the past several years. when I clean it out in the spring I’ve found 3 or more dead/decaying frogs on the bottom or in crevices between rocks. This fall I’ve noticed several frogs happily enjoying my pond. How can I help these guys survive the winter? Thank you.
    Instagram photo of one of my frogs: https://www.instagram.com/p/BKp9YSfDvP6/

  19. Yesterday, a birdhouse, we had nailed to a tree, came down and I found 3 tree frogs inside along with shredded bark and debris. The house had been in the tree for 5 years or so. It was in the 50’s yesterday and dropped down into the 30’s last night. I had brought the frogs into the garage and put them in a container with a paper towel. Today is sunny and the temperature is suppose to get to 64. Can I release these little guys today near the tree I found them in? I live in SW Ohio.

    • Hi Jo,
      With the weather being so unpredictable, it’s tricky to advise. Although it could be in the 60s, it could drop quickly before our frog friends can find a place to hibernate. Perhaps consider taking care of them through the winter?
      Please keep us posted.
      Susan

      • I ended up letting them go near the tree I found them in. Actually, it’s on the edge of our woods so there was tall grasses. I also put some of the shredded bark back into the old nest box and laid it beside the little frogs with the entrance hole right in front of them. After reading your advise, I just checked on them and didn’t see one. Maybe they went back into the nest box. I will leave it alone for now and check in the spring. Thank you for your response. I appreciate it. They’re so cute and I’m hoping they’ll be okay now. :)

  20. Thanks very much for the info on this site. Here is what I do with the frogs in my small pond. We live in Michigan, north of Detroit. Our pond is adjacent to our patio. It’s 3ft across and about 15-18″ deep. There are 3 ledges for aquatic plants in pots to sit on. I close the pond in Oct. and reopen in April. I keep water in the pond all winter so that the lining doesn’t crack during the winter. I cover the pond with chicken wire during the winter and place bricks or large rocks around the perimeter of the chicken wire so that no stray frogs can get in and become frogsicles. I always find many frogs in my pond throughout the summer. When I clean the pond in Oct., l scoop out all the frogs into a bucket and take them to the neighborhood wetlands on the next street. I’ve had as many as 9 frogs living in my small pond at the same time. I have been doing this for about 15 years and it works for me.

  21. I live in Lake Wylie, SC, and I brought my houseplants inside the other day. I quickly found out I had a green tree frog who made a home in 1 of my plants on the 3rd floor. So I put him outside on the patio. The next day I look out to the empty patio to see the little frog sitting on the cold concrete floor, so I grabbed a small plant for him that sits in a water bowl. Within a few seconds it jumped in and hasn’t left for 3 days. I’m writing, because I’m concerned for the little frogs safety since the nights have started to get in the low 30’s. Should I bring it to the nearby pond?

    • Hi Jessica,
      So long as it’s not too cold yet, yes the frog should be all right if you bring it to a nearby pond. Otherwise you may have to bring it inside till spring.
      Thanks, Susan

      • Thank you for the quick response! I will bring Hector the green tree frog to the pond tomorrow, since my husband won’t let me keep him. Fingers crossed he will be alright and safe!

          • Well, some frogs can freeze during the Winter and thaw in the Spring and hop along their way. If you are worried about a local frog and feel it’s too cold out, perhaps it is and you can bring inside thru the cold months?

  22. Hi there is a green frog has been just there for a few days without moving it is geting colder for the winter im afraid on a freezing night it wont survive, i placed a decoration mesh around where he is to shield the wind hope he will be fine any ideas?

  23. I have a few tadpoles that I got from a puddle in August. They are american toads. It is November now and most have their back legs, only one has front and back legs and is out of the water. I didn’t relize when I took these little guys from the puddle that it would take so long for them to turn into frogs. I thought I would be releasing them before the cold set in. Now I don’t know what to do with them for the winter. The one that more is very tiny, smaller than my pinky nail. Any suggestions?

    • Hi Susan,
      Where are you located and what is the current temperature and near future forecast? Would you be able to bring them in and see them through the Winter?
      Sue :)

  24. Thanks for this site:)
    Live in Pa and have a lovable medium size bullfrog living in my aboveground antique bathtub pond….with rocks and fountain. I did place pcv tube with leaves at the bottom of the pond for hibernation. I do have a de-icer to discourage ice from forming on pond….
    Is there anything else I can do to assist my bullfrog thru out the winter?
    It’s mid November and my bullfrog is still active….he ate a big earthworm today:)

    Thanks for advice:)

  25. Hello! Hoping you can give some advice… We had a pondless waterfall installed this fall and have recently shut it down. There is about 8″ of water left in the reservoir at the top of the waterfall and we found two adult leopard frogs in that water. Since we live in MN and the temps are below freezing, we brought the two frogs to the backyard where we have a very large residential pond (doesn’t freeze out in the winter.) The next day, we found another adult leopard frog in the reservoir. We repeated the process and once again in the morning, there was another adult frog in the reservoir. I can’t believe that the adults are making their way back into the reservoir at the front of our house (quite a distance from the back pond), especially now that there is some snow on the ground. I plan on relocating the frog again tonight, but what’s your thought on this? Could frogs really be this insistant on staying where they think they should hibernate? Thanks!

    • It is so very interesting and yes, perhaps that’s where they wish to be. Because the weather has been cold, then hot, then cold, perhaps they are a bit confused. Keep an eye on them and if needed try to bring them inside for the Winter.

  26. Cute Little Frog in My Olive Tree

    Greetings,

    I live in Northwest Arkansas and brought my houseplants in for the winter a couple of weeks ago. Shortly thereafter, I had an attach of aphids and small plant flies. I immediately separated the affected plants from the others and researched natural pest killers and deterrents. I ordered neem oil and when it arrives, I’ll make a horticultural soap spray everything down and cover the top of the soil with sand. In the mean time, I shopped up banana rind and pushed it under the soil of all the plants.

    This is where the frog in my olive tree comes in.

    One of my house plants is a 5′ potted olive tree that enjoys it’s summers on the patio in full-to-partial sun. In an effort to naturally keep pests away, I placed a chocolate mint plant and cedar wood chips in the pot on top of the soil.

    When addressing the infestation (exaggeration, it’s very mild), I pushed aside the cedar chips in several areas around the base of the olive tree to place the banana peel under the soil. A day later, I was checking the plants and found the cutest little frog curled up in one of the branches. He hasn’t moved in days. I can see his pulse beating and sometimes it even looks like his eyes are open. But he doesn’t move.

    He’s been inside now for the last couple of weeks. The outside temps range from frosty nights to days that can range anywhere from 40 – 70 degrees.

    To be honest, I love having him in the tree and would love to just leave him there. But I want to do whatever is in the adorable little fellows best interest.

    Any advice you can provide would be most sincerely appreciated.

    • Hi! It does sound like the frog is totally happy where it is… would you be able to buy some little bugs and keep it inside for the winter? Can you send a few photos to info@frogsaregreen.com of habitat and the frog?
      – Susan

  27. I have grey tree frogs that we have been protecting that hatched out in early Sept. It is now turning cold and they are about the size of my pinky nail as they climb out. Do frogs this tiny survive the winter outside. I live in Central Ga. Right now we have built a little sanctuary with plastic over a table and pushed the containers under there. The water is heated and the tadpoles are still growing legs and hopping out but they are really tiny and we have had some really cold nights. One climb out today and kept jumping onto my clothers like it was expecting food and warmth.

    • Hi Jan, Thank you for your query and for caring about frogs. I will consult with a few colleagues as well as research more and write back very soon.
      Susan :)

  28. Hello, my kids raised Grey tree frogs last spring, of the 10, we kept 4. We put them in a terrarium. In August, 3 mysteriously disappeared..it was during a period of 3 days when we were not home much, we did check/feed them nightly..then suddenly they were gone. My daughter took the remaining one to college. She was hand feeding it and it was growing nicely. Over Thanksgiving, her friend was watching/feeding it. Then suddenly it was gone. Her friend said she was very careful with the lid. We have dug about a quarter inch into the dirt but we can’t find it. Other then the obvious escape, any other suggestions? Thanks

    • Hi Sue,
      There could be a few possibilities, but the most likely is they escaped to find a mate, food, or hibernate. Hard to know. About how big where they and are you located near any ponds or wetlands?
      Susan

  29. I found my resident tree frog inside my house today, looking not so well…not sure how long he’s been around with no food or water. At first I put him outside, but then realized it was probably to cold for my little buddy. He’s currently in the garage on a plant that we keep inside during the winter months. It’s low sixties today and mid-50’s tomorrow, with freezing weather coming in on Friday night. Will he have time to find a hibernation spot if I put him outside today? I’m worried about him, but am sure he will not stay on the plant through winter and won’t be able to survive in the garage……and am not sure I can handle feeding him crickets for 4 months if I put him in an terrarium. :(

  30. Hi, I live in Northeast Ohio; lots of frogs live in the pipes that drain from our houses and gutters in our neighborhood. Today, my kids found a frog just outside one such pipe, in the road. It’s January, but yesterday it was 56 degrees and very rainy, then it froze overnight. The frog seemed to be headed toward hibernation, since it barely waved its legs when I picked it up. I put it back in the pipe, because I didn’t want it to be run over.
    My question: Will it be able to overwinter in the mouth of the pipe (It’s about 3-4 inches wide, I can’t get it much further back than one foot) or does it need more in the way of shelter? The naturalists at the nature center told us not to take frogs into the house, then release them in the wild because after a month, the frog will have different bacteria than those in the wild. and could wipe out other wild frogs. So if I bring it in, it would probably be for good.

    • Well, the issue is that the frog may have frozen and not had time to find a place to hibernate. I would suggest checking on it and if you can, bring it in. In one case, someone took the frog into their basement and in another case their garage. There can be places where they are closer to being outdoors, but not. – Susan

  31. We have recently discovered a frog in a house plant which we brought in for the winter. We expect that he jumped in there in the summer and has spent the past 5 months in our house. We know very little about frogs and were wondering what all the “chirping” means. When he does this, we put water in the plant which seems to quiet him down. Can you please tell us about “chirping”. We live in southern Ontario

    • Hi Nancy, what a surprise I’ll bet! Let me look into Ontario frogs and will write again soon with details and recommends. Thank you for caring for it during the winter. – Susan

  32. Hi, i live in Australia and we have a large amount of green tree frogs on our farm.We have only recently moved here and have had a problem with them on our glass sliding doors. I’ve been told they catch the bugs that come to the light at night and flies. Our problem is that they crawl in between where the doors slide and stay where they cant be seen. I think you can guess where this is going? We have no idea they are there..no sound.. no sight.. until we open the door. Then its too late. Its horrible. We have asked locals and many of them have the same problem. Is there a way we can keep them away from the doors?

    • Dear Janine, Wow, that’s awful. I sure haven’t heard this before. I will post this on our Facebook page and see if we can’t get a few suggestions.
      Susan

    • Erica,
      If you are keeping the frog inside for the Winter I suggest you visit a nearby pet shop or nature center, so you can take proper care of the frog.
      Susan

  33. Hello.
    I have no idea what kind of frogs live around here but we found, what looked like, a frozen frog near our gutter chain. Last year we had a hard winter and under our gutter chain we now have a two foot sink hole. Yesterdayit was a bit warmer than it has been, around 35 – 40 degrees, so we decided to fill it with some sand. This morning we noticed the frozen frog on top of the sand. What should we do, leave it or bring it in?

    • Janet,
      Thank you for writing. Do frogs show up and disappear often? Most likely the frog is looking to hibernate and that is a good spot…?
      Susan

  34. Hi I live in Dalton Ga. and I just found a green frog behind a plastic bag lying on the concrete floor of our garage. The temperature is 19. Would have left him out there if it wasn’t lying on the cold concrete. Should I make some sort of shelter with leaves and such? I’m sure he’s gonna get active shortly now that i’ve brought him inside. Any advice would be greatly appreciated
    Thanks Melinda

    • Dear Melinda,
      Very sorry for the delay in responding! Since you brought the frog inside, yes you’ll need to take care of it through the Winter. I’m sure you already consulted with a local pet store or nature center. Please let us know what you did and the state of the frog. If you can tell us your location and send a photo of the frog, that would be great!
      – Susan

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