Bees aren’t ALWAYS trying to chill out–they’re busy! Here are a few reasons our honeybee sisters might need to get warm quick.

Protect the hive!

Beat the freeze!

To stay warm in the winter, worker bees pack in tightly around the queen and shiver their flight muscles.

As bees near the inside of the huddle get too hot, they move outward, allowing the layers of colder bees that served as insulation at the cluster’s edge to get warm.

Stay healthy!

Sometimes “chalkbrood” spores infect a hive’s bee larvae, turning them into white lumps that look like … well, chalk. If bee larvae are infected with chalkbrood, the whole colony will give itself a fever. To stay well, workers heat up the brood combs, preventing the spores from developing inside the larvaes’ guts.

Written by Meghan Barrett and illustrated by Keren Albala.

Barrett is currently a Biology PhD student at Drexel University, studying an expanded version of “bug brains.” When not fawning over native bees as part of her Bee Bytes initiative (byte-sized introductions to the bees of the US), she spends her time writing ecological poetry and science plays (or dabbling in #scicomm). More about her work can be found at; you can find her on Twitter (@Bee_Bytes).

Albala is an animator, illustrator and VFX artist working in Los Angeles, CA. She has created animated content for museums, science programs and documentaries, as well as 3D previsualization for Disney, Marvel and Universal feature films. Currently she divides her time between animating, teaching, playing in a ukulele orchestra, exploring the natural world, and jumping into leaf piles with her toddler. Find out more at or follow at @kerenheron.

Check our facts!

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Acra M, Papachristoforou A, Mougel F, Rortais A, Monceau K, Bonnard O, Tardy P, Thiery D, Silvan J, Arnold G (2014).

Defensive behaviour of Apis mellifera against Vespa velutina in France: Testing whether European honeybees can

develop an effective collective defence against a new predator. Behavioral Processes, 106, 122-9.

Stabentheiner A, Pressl H, Papst T, Hrassnigg N, Crailsheim K (2002). Endothermic heat production in honeybee winter clusters.

Journal of Experimental Biology, 206, 353-8.

Starks P, Blackie C, Seeley T (2000). Fever in honeybee colonies. Naturwissenschaften, 87, 229-31.

Sumpter D, Broomhead D (2000). Shape and Dynamics of Thermoregulating Honeybee Clusters. Journal of Theoretical Biology,

               204, 1-14.