I was recently sent this intriguing question from a reader:

Dear Dr. Dolittle,

I heard in my science class that because honeybees have such high blood sugar levels, they can survive freezing…is that true?


To answer this question, I turned to expert Dr. John G. Duman from the Department of Biological Sciences at the University of Notre Dame who studies antifreeze proteins in insects. Here is what he had to say:

In short, no.

Insects generally survive subzero environmental temperatures by evolving one of two strategies. Some are freeze tolerant, meaning that they can survive the freezing of their body fluids. In contrast, those species that die if frozen must evolve seasonal adaptations that prevent freezing of their body fluids in winter, such as various antifreezes that make them freeze avoiding. (For a recent review of this topic see the book Low Temperature Biology of Insects, edited by D. L. Denlinger and R. E. Lee, Cambridge University Press, 2010). However, honeybees are neither freeze tolerant nor freeze avoiding. They die of hypothermia if their body temperatures are lowered to approximately 7 degrees C. In fact, they are endotherms. Like humans and other mammals, they control their body temperatures by producing internal heat, mainly by shivering their flight muscles. In addition, they huddle together into a large mass that conserves the heat produced by the individual bees. Individuals within the cluster move in and out between the center and the outside edge of the cluster. This combination of endothermy and clustering keeps their body temperatures well above freezing right through the winter. In one experiment, when the air temperature around the cluster was kept at 5 degrees C, bees at the center of the cluster had body temperatures of 35 degrees C and temperatures of individuals on the outside edge were approximately 19 degrees C. The center of the cluster generally stays between 30 and 35 degrees C even at outside temperatures as low as -30 degrees C.

A number of insects, especially bees, wasps, and certain large moths are endothermic during the warm months, using the heat produced as a by-product of the flight muscles to maintain their thoracic temperatures. However, very few species remain endothermic through the winter. One serious problem for maintaining endothermy at low temperatures is that it becomes very energetically costly, requiring large amounts of food. However honeybees are able to remain endothermic because the honey that they have stored generally provides a sufficient energy source to get them through the winter.

If you have a question for Dr. Dolittle, please send it to drdlttl01@gmail.com.


  1. #1 Charles Wade
    July 19, 2011

    I am a high school science teacher, and I really appreciate this answer. I had never thought about it but now I am prepared for interesting discussions about endothermic bees and sugar as an energy supply- Thanks!

  2. #2 Vince whirlwind
    July 20, 2011

    Yes, bees hate getting cold. Once they are cold, unless they are in their box, they will surely die, because they can’t warm up again.

  3. #3 justin tv
    August 4, 2011

    I agree “bees hate getting cold. Once they are cold, unless they are in their box, they will surely die, because they can’t warm up again”

  4. #4 tayfun
    August 5, 2011

    Aydınlattıgınız için teşekkürler hocam.

  5. #5 Edward M Randall
    science hill, kentucky, 42553
    October 16, 2014

    We found a large wasps nest on the house overhang and was able to take it down in one piece. My wife wants to take it to school for her science class. i have put the whole nest in our chest freezer hoping this kill the wasps in it. Will this do the trick?? thank you Edward Randall

  6. #7 Jay
    February 3, 2015

    Large wasp in my garden in freezing temp for days ( nights) today I brought him indoors. He then started to move his wings and legs. Amazed!

  7. #8 jay
    February 16, 2016


  8. #9 Mike
    April 26, 2016

    Alright jay, no need to shout…

    Anyway, Do you have a reference for what you have written about them dying of hypothermia?

    All the best

  9. #10 Garry Allan
    Winnipeg, Mb. Canada
    May 15, 2016

    Question re bees: My understanding is that bees are in danger of not surviving temperature below 5 degrees C. What about the eggs? What temperature can they withstand?

  10. #11 chuck B.
    Almond, Wi.
    May 16, 2016

    I live in an area that can get down as low as -25°F in the winter and I have just started a new bee hive this spring. Should i take added protection to the hive in the winter time like cover it up or?

  11. #12 Garry Allan
    Winnipeg, Mb.
    May 21, 2016

    Chuck: absolutely the bees need protection at temperatures below 5 degrees C. I’m no expert as you can tell from “Q” #10, but for what it’s worth, keep a small# of hives in a heated 8×10 storage shed. Keep temperature between 2 @ 5 degrees C. Lower & they could freeze, higher & they’ll be more active than you’d like. If she’d not available, wrap with some seriously insulated covering & moderate temperature.

    Anybody got an answer to my “Q # 10?

  12. #13 Martha
    January 5, 2017

    We had a 46 degree high temperature yesterday so I noticed many bees came out of the hive – not a lot, but some. I noticed after the temperature dropped, they all were back inside. There were a few dead ones remaining on the lid, or area in front of the entrance. After a night of freezing temps, I went out this AM, & brought in one of the dead bees. We like to examine them when we see them to look for mites. There were no mites, but my husbsnd was away at the time & I thought he’d like looking at it too, so I payed it on a napkin. An hour &1/2 later he retutnrd, & low & behold, the bee was moving around on the napkin.