Snow Fleas

Snow Fleas “pepper” the snow in March.

I’ve always admired teachers who have led their students to be observant and intellectually curious. Charlotte, who has the uncanny ability to find mushrooms and also the tiniest of fungi, fits this description perfectly. The outdoor temperature this past February 24 reached 34 degrees F. and she was quick to notice the first Snow Fleas of the year “peppering” the snow along our front sidewalk.

Today as I write this, March 6, the temperature is slightly above freezing and again the snow bank along the front walk has literally thousands upon thousands of these tiny, living, dark blue-gray, slowly-moving and sometimes “jumping” flecks, also called Springtails, highlighted by the clean snow. It is especially on the snow near the slightly thawed ground along the edges of our flowerbeds bordering the front sidewalk that they are abundant.

It has been said that great things come in small packages, and Snow Fleas surely are small, between an eighth and a sixteenth of an inch long, or roughly two millimeters. It should be quickly added that they are not even remotely related to the parasitic fleas which may, for example, present problems to one’s pet dog. They are also not true insects either, being about as closely related to insects as mammals are to reptiles. As described in insect field guides, they are insect-like arthropods and are among, if not at the top of, the list of the most abundant creatures living in our county. Their greatness comes from their being such valuable recyclers.

Small groups of Snow Fleas are very likely mating on the wet driveway.

Here is another piece of related nature trivia. A lot of people would assume that species such as the White-tailed Deer, Gray Squirrel, Cottontail, or one of the various species of mice would rank as the most abundant mammal in our county. Actually it is the Short-tailed Shrew that takes this honor, and yet so few people ever actually see one, simply because of its highly secretive lifestyle. And the same holds true for the lowly Snow Flea. What many people call a Meadow Vole, perhaps seen feeding on fallen seeds below a bird feeder, often turns out to be a Short-tailed Shrew, similar in size and even color of fur.

I’ve had phone calls in past Marches from concerned people with the typical comment, “There are thousands of these tiny dark things on the snow, like grains of pepper, some suddenly jumping out of sight. Are they fleas? Will they get into the hair of our dogs or even into our own hair?” The answer is they are truly harmless. In reality they are a tiny fraction of the marvelous complex of organisms that break down leaf litter and other organic matter on the forest floor. They are an obvious benefit to trees, wildflowers and other plants and animals of the woods. Living plants can then make use of the remaining nutrients. Finally, completing the cycle, people and other woodland animals can make use of the plants. Snow Fleas could accurately be described as one of nature’s recyclers of organic materials and are good soil builders.

Snow Fleas on Charlotte’s fingertip.

Most often, field guides refer to them as arthropods called Collembola (kol-LEM-bo-la). What’s so truly amazing is that their bodies contain a rare glycine-rich anti-freeze-like protein enabling them to remain alive and active in below-freezing conditions. This special protein prevents ice crystals from forming and bursting cells in living tissues. Researchers are interested in developing ways of using similar proteins in our lives, for example in making better ice cream and especially in treating living human organs which are to be transplanted in another person.

Their descriptive nickname of “Springtail” refers to two relatively long objects, appearing in a microscope like miniature tails extending outward from their abdomen, or rear body part. These forked tails, called furcula, can be folded and hooked into place under the body. When the Springtail releases the hooks or catches, the tiny creature “springs” into the air for several inches. In other words, each Springtail has a built-in catapult system.

Requiring a constantly moist environment, they live in soil, leaf litter, mosses, fungi, or along shores of ponds. We enjoy our hikes down our 950-foot-long driveway out to the mailbox. During the next few weeks the tracks of the many unwelcome messy and destructive wild Turkeys will be liberally peppered with Snow Fleas as will all the other wild creature tracks.

In recent years the greatest number of the Snow Fleas appeared near the end of the driveway, where it slopes slightly upward to meet the blacktop. Here drainage of the melting snow gradually fills in one of the mailman’s tire tracks near the mailbox with an inch of water which, at first glance, appears like dark oil. Upon closer inspection the darkness is attributed to virtually millions of Snow Fleas having been carried into this little reservoir by melting snow.

Hundreds of Snow Fleas gather on the snow near the Lukes’ home.

One can closely observe several of the tiny rivulets to see the Snow Fleas being carried merrily along. Their diminutive two-millimeter size, plus the fact that their bodies are covered by a meal-like powder and small hairs, makes them float easily upon the surface of the water.

Springtails are most active from November through March. It is in spring that mating takes place and when females will lay eggs in the soil. Tiny Springtails, referred to as nymphs, are born. They don’t look exactly like the adults but as they eat and grow, shed their outer skin (exoskeleton) several times, by late fall they will look just like the adults. Their food will consist of molds, decaying vegetation, algae, bacteria, fungi and microscopic animals such as roundworms and rotifers. Predators include beetles, ants, mites, centipedes and other small insect-eaters.

These mysterious little insect-like creatures, perhaps directly descended from the unknown wingless ancestors of winged insects, are to be admired and then ignored. They will go their way and chances are you will not see these highly valuable creatures again until just that next perfectly wonderful and welcome snow-thawing day in March.