Kelly found snow fleas in just about every horse-hoof mud puddle in the Sapphires. She writes, “There were hundreds in each little pool of water, and they were so tiny it was hard to get a decent photo.” These are the same guys you see “sprinkled” across the snow in the winter. For whatever reason, they tend to group up in puddles just as the snow disappears. 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.
Size: About 1/16 of an inch long
Photos by: Kelly Dix on 4/22/22 in the Sapphire Mountains, MT