Now that we are back in the double digits, some of you may be wondering, what is out there moving around the Arb? Mice can be found hopping through the snow and the shrimp are active in Spring Creek, but there is another, often overlooked little creature that begins moving about on warm winter days. This creature is the snow flea. Interestingly, it is not a flea at all, despite its name, and is in fact a type of springtail. Until recently, springtails were considered to be insects, but are now grouped in a different phylum altogether.

Springtails were among the first of the modern hexapod groups to develop, emerging some 420 million years ago. Most species are quite small (less than 6 mm), possess six legs, and another “tail-like” appendage called the furcula. When a springtail senses a threat, it propels is furcula down against the ground, the force of which sends the creature high into the air. Most predators of springtails have poor visual acuity, so this evasive maneuver seems to make the springtail vanish mysteriously before the predator’s very eyes! They can launch themselves several inches at a time.

This particular springtail, the snow flea (Hypogastrura nivicola), is a dark blue and can be found jumping on the surface of snow, often in small depressions or around the bases of trees. Their preferred food source is decaying leaf matter, so keep an eye out in forested habitats (I recommend the woods along Spring Creek). They may look like soil particles, but their movement gives them away!

You may be asking yourself, how do these small creatures not freeze while we are outside desperately layering to avoid frostbite? These creatures have managed to develop an antifreeze protein that allows them to function in very cold environments. Ice growth on tissue leads to the dehydration and rupturing of cells. Their antifreeze protein binds to this ice crystal surface, making it more difficult for subsequent water molecules to bind and inhibiting further ice growth. Don’t worry if you see a snow flea! They have no desire to follow you home or live on your dog, but simply want to spend the winter munching away in a world temporarily free of predators and filled with snowflakes.