Recently, someone brought snow fleas to the extension office for identification. Most folks have never seen snow fleas or even heard of them. As their name suggests, snow fleas are tiny arthropods that are active outdoors during the wintertime. If you are outside on a sunny winter day, take a close look at the snow, especially where it has melted a bit around the base of trees or near the house foundation. Snow fleas are tiny, (1/32 - 1/16-inch) and look like someone spilled pepper on top of the snow. If you look even more closely you may see them moving. Folks also may find them on sidewalks and concrete near their home, but the snow fleas are easier to see when their dark bodies contrast with white snow.
A snow flea produces a unique antifreeze-like compound in its body that allows it to be active when other arthropods are dormant. A researcher at the University of Wisconsin is studying an edible antifreeze made from gelatin, which is very similar chemically to the one found in snow fleas. Eventually, this compound may be used to keep ice crystals from forming in ice cream.
Snow fleas are a species of dark blue springtail (Hypogastrura nivicola). Springtails have six legs, like insects, but entomologists separate them from true insects because they have internal mouthparts and other structural differences. Springtails are ancient organisms - fossils have been found and dated to be 400 million years old. This photo was taken by Vicki Jedlicka, Lancaster County Extension Media Assistant.
Despite its name, the snow flea is not a flea, and it does not bite or feed on animals. Springtails live in damp areas of the soil, or under leaf litter, where they feed on fungi, algae, and decaying organic matter. A springtail does not have wings, but uses a tail-like apparatus to jump (hence, the name springtail). Most springtail species are not active in the winter. They are extremely common in the soil. It is difficult to calculate numbers, but there can be thousands to millions of springtails in a cubic meter of soil.
After a lengthy period of wet weather, springtails can occasionally come into homes through tiny cracks and crevices in the foundation. Reducing humidity usually will solve a springtail problem. Some species are pests of commercial mushroom production.