While snow fleas are active all year round, these tiny little guys are much easier to see after the snow flies, looking like someone sprinkled pepper on top of the snow. Once considered insects, they belong to a group of arthropods called springtails, and along with the orders Protura and Diplura comprise the class Entognatha (meaning “internal mouthparts,” as opposed to insects, whose mouthparts are external).
The species commonly seen in western Montana are only about 1/16 inch long. Snow fleas get their name from their ability to leap. By hooking their “tails” under their body, the release can propel them into the air many times their body length. Living in the soil and leaf litter, they eat decaying plant matter, bacteria, fungi, algae, pollen, roundworms, rotifers, and sap. Snow Fleas have an “antifreeze” protein that prevents ice crystals from forming in their bodies and allows them to survive sub-zero temperatures. Photo by Glenn Marangelo on 12/27/20 in Pattee Canyon Recreation Area near Missoula, MT.