They Really Aren’t Fleas

It seems to me that, in the past few years, each winter we have less and less snow cover. I wonder if it’s a long-term trend because of climate change. I am also curious about how this might affect the health of dormant plants and animals. A blanket of snow protects and insulates plant roots, keeping them from drying out in cold winter winds. Snow helps predators track and hunt, and mice and voles burrow under the blanket for protection.

Nearly all the snow has melted from the foot or so we received a few weeks ago. After a fresh snowfall I like to check out local natural areas in my neighborhood to see who’s been around. I miss doing that. But as the snow was melting, I did notice tiny twenty-fifth-inch to sixteenth-inch (1–2 mm) flecks peppering the snow. On closer examination, they were “Snow Fleas” hopping around next to a tree trunk.

Snow Fleas are not parasites and don’t bother you or your pets at all, unlike true fleas. But like true fleas, Snow Fleas can jump great distances for their size. For this reason, they are also called Springtails. They were once classified as insects, but now are in a separate group, in the subclass Collembola. Most species have a forked tail-like appendage called a furcula. It’s the furcula that acts like a spring, propelling them into the air.

How can Springtails be active in winter’s bitter cold? Springtails have antifreeze proteins that are rich in the amino acid glycine. This protein attaches to ice crystals as they form in their bodies and prevents the crystals from getting larger. Some scientists speculate that Springtails come up to the surface of the snow because of overcrowding, or possibly lack of food. They will, however, return to the leaf litter below. Springtails feed on fungi, pollen, algae, and decaying organic matter.

So as the next snowfall melts, look for tiny, pepper-sized “flecks” jumping around and be thankful for them. Just like many other decomposers, such as fungi, bacteria, isopods, and more, Springtails are vitally important in breaking down leaves and other organic material into soil beneficial to plants and, in turn, animals like us. As the biologist E. O. Wilson said, “It’s the little things that run the world.”