Conservation Corner: Snow Fleas  

By Dan Zarlenga,
Missouri Department of Conservation

Photo Caption: Snow fleas are not really fleas at all, but actually springtails.

Photo from Flickr courtesy of Christa R. http://short.mdc.mo.gov/Z9F.

Do the cold weather and short days of January give you cabin fever? Are you itching to get outside? The next snowy day, scratch that itch to go out and explore, and you could just find some snow fleas.

If you thought that creepy crawlies just stayed huddled up and dormant in their homes during the winter, you’re in for a surprise. Right after it snows, take a hike into your back yard, local park, or conservation area, and look for a mass of black specks in the snow. You might find them near the base of a tree. sprinkled along a snowbank, or clustered inside the depressed area of a footprint. These are tiny, insect-like creatures known by folk wisdom as “snow fleas”.

These snow fleas are not really fleas, but actually springtails. Springtails are a class of insect-like critters, but biologists don’t classify them as real insects. While springtails do have six legs, they do not possess wings like true insects. Four orders of springtails occur in North America; the ones we see in the winter snow are of the water springtail order. During the warmer months, you might spot water springtails floating on the surface of ponds and other still water, and bunches of them on banks or objects sticking out of the water.

Water springtails tend to be gray or black with smooth bodies that can be either velvet-like or grainy in texture. Their tiny bodies are plump and oval, with short legs and stubby, four-segment antennae.

Many springtails do have some spring in their step. They can literally jump using a forked tail-like structure on their abdomens. Called the furcula, this pseudo tail quickly unfolds to cause the critter to spring up to several inches in one leap. That’s one epic jump for something that’s only about three millimeters in size. It’s this trait that gives them their name. The same behavior might also help explain why people association them with fleas. But don’t be concerned; these false fleas will not infest you or your pets. They are completely harmless. Just a bit of a surprise to see in the middle of winter.

What magic, then, do springtails possess that enables them to survive the dead of winter? Scientists have identified an anti-freeze-like protein in their bodies that allows them to operate in sub-zero environments. They’ve also found it to be rich in the amino acid, glycine, a substance which helps our bodies produce proteins. So, these simple creatures essentially use a form of anti-freeze they create themselves to endure winter’s cold. How amazing!

Springtails are often seen on warmer days in winter when the snow is melting and these “snow fleas” are rising to the surface in search of food, which takes the form of various organic compounds. Look carefully and you might see swarms of them sprinkled over the snow, like specks of pepper on a white linen tablecloth.

So, if these tiny creatures can brave winter’s chill, maybe you can too. Put on an extra layer and venture forth after it snows with a keen eye. There could be some snow fleas out there awaiting your discovery. You can rest assured that the desire to get out and explore will be the only itch you’ll feel.