Their name aside, snow fleas are not fleas and they never bite. They belong to a primitive wingless group of insects called Collembola or springtails. Most springtails are less than 6 millimeters in length. Snow fleas mature in November and are active until late spring. On warm sunny days they travel up out of the leaf litter and search the snow for tiny bacteria, fungi and algae to eat.
Snow fleas can remain active in the cold partly because they are dark and absorb heat from the sun.
There are 677 species of springtails in North America and all are harmless to humans. Springtails eat fungi and decaying leaf litter and are extremely important in the production and maintenance of our soils and should not be considered pests. Read more about Collembola in the Wisconsin Natural Resources Magazine.