Snow fleas

These springtails, about the size of a peppercorn, owe their name to the fact that they are often seen on the surface of the snow, in the winter or spring. Though very small, they are easily visible thanks to their contrasting dark colour. Springtails sometimes gather in huge numbers, often near tree trunks, after climbing through the snow to feed on the surface.

Snow fleas survive the winter thanks to a glycine-rich protein that acts as a sort of antifreeze by limiting the size of the ice crystals that form in their bodies at low temperatures. Research at the University of Chicago has shown that some species of springtails can survive extreme temperatures as low as –60°C. It is hoped that this protein can be used one day to help conserve organs for human organ transplants.

Like other springtails, snow fleas jump not with their legs, but rather by using the furcula, a fork-shaped organ held under tension beneath the abdomen by two hooks. When a springtail needs to move more quickly than by walking, it releases these hooks and the furcula snaps against the surface and flings it into the air. This is where the name “snow flea” comes from, although they are not fleas and do not bite.