Look for snow fleas gathering at the base of trees on sunny days in February and March.

Location: 
Cook County
Date: 
02/04/2008
Description: 

On a warm, sunny winter day, take a look at the base of a tree where the snow may have melted down to expose some leaves, or where the snow is shallow or hollowed out just a bit. There you'll find a sprinkling of what looks like "pepper" or "ashes" on the surface of the snow. Each speck you see is a snow flea. Once you find them, watch closely and see what they're up to. Snow fleas are actually tiny insects which come out on warm, sunny days to eat decayed plant material or sap oozing from the tree. They hop around acting like fleas and that's where they get their name, snow "fleas." They're not fleas though, but actually an arthropod called Collembola (kol-LEM-bo-la) or commonly called springtails which measure about 1/8 inch (2mm) long. They have a very unique catapult system to get around. Two "tails" on their back end are tucked up underneath their belly, held in place by tiny "hooks." When the springtail wants to move, they just release the spring-loaded "tails," called furcula, which hit the snow and send them flying into the air. Since snow fleas can't conrol their flight or direction, they frequently land in the same spot or only a few inches away.