The National Enquirer could get some mileage out of snow fleas, if only it were entomologically inclined - and had a microscope. Not only are these minute creatures not fleas, they may not even be insects, according to some scientists.
Chances are that you have seen snow fleas in snowy woods, but you may have mistaken them for small specks of dirt. As specks of dirt go, they accomplish quite a bit. Snow fleas form congregations of up to a million individuals and they migrate en masse for a distance of about 25 meters. Before you scoff at this distance as insignificant, consider how tiny these creatures are; at about two millimeters, they travel 12,500 times their body lengths. This compares to a 13-mile hike for a five and a half foot person.
Snow fleas are in an order called springtails which, along with the bristletails (scientifically, Collembola and Thysanaura), are different enough from other insects that some scientists would have them kicked out of the class Insecta. Neither group has wings, they have too few body segments, and they have other anatomical aberrations as well.
There are more springtails on land than any other insect and if they were white instead of black, we would see them in leaf litter all summer. On warm winter days they leave the duff for Unknown reasons and emerge through holes in the snow made by grass stems or trees. There they jump around together on the snow surface, returning by the same route at night.
Lacking the powerful legs of a true flea, they use an unusual mechanism to get themselves airborne. The animals curl themselves up and two prongs near the end of the abdomen are caught around a pair of hooks farther forward. When the hooks are released, the prongs hit the ground and propel the snow flea into the air.
It's a pleasure to come across any form of life in winter woods, and if you can imagine being two millimeters long, you may find that, far from being alone, you have up to a million lively companions.