Eeek! What Are Snow Fleas?

Eeek! What Are Snow Fleas?image preview

One of the greatest joys of cold weather is the lack of bugs. When the temperatures dip in winter, it becomes an inhospitable climate for many of the creepy crawlies that make our lives miserable in the spring and summer — fleas, ticks, stinkbugs and the like. But it turns out, there’s a little known critter known as the snow flea that makes its home in snow banks and the sprinkling of snow around the tree trunks in your yard.

But there’s good news! There is no need to fear the snow flea. They don’t bite and they are actually very good for the environment!

What Are Snow Fleas?

Snow fleas are not actually fleas — and officially, they aren’t classified as insects, either, though they do look like bugs. These small wingless creatures are often referred to as “springtails,” but their scientific name is Hypogastrura harveyi or Hypogastrura nivicola, depending on the species. Snow fleas are classified as hexapods, which is a subtype of the arthropod family. Like insects, snow fleas have six legs but researchers say that they are more closely related to crustaceans.

The Reason Behind the Name

If snow fleas aren’t fleas, then how did they get that name? There are a couple of good reasons. First of all, these small creatures happen to look a lot like fleas. During warmer periods in the winter, when snow melts, these critters can be found speckling the snow.

Snow fleas also have the same super-powered jumping ability that regular fleas have. But unlike cat and dog fleas, which use powerful, enlarged hind legs to leap long distances, snow fleas have a sort of tail (called a furcula) that is responsible for their jumping. As the furcula unfolds, it launches the snow flea over large distances — hence the name “springtail.”

How High Can Snow Fleas Jump?

Snow fleas jump around on top of the snow, traveling up to several inches in one leap.

No Need to Fear! Snow Fleas Don’t Bite!

Though they look and act like cat or dog fleas, snow fleas are not parasitic, which means you and your pets are safe. In fact, if you enjoy gardening, then you’ve probably encountered thousands of snow fleas in your lifetime without ever realizing it. In the summer, they tend to sit on top of rich topsoil but because they are so small and dark, most people don’t notice them. That soil is actually the snow flea’s food source. They are an essential component in the ecosystem because they feed on decaying organic matter in the soil, thus helping it to decay faster, turning it into plant food.

Why Do Snow Fleas Come Out in the Snow?

Perhaps the most interesting thing about snow fleas is the way they come out in the winter, dotting melting snow instead of remaining in a period of dormancy like their insect and arthropod cousins. This is because snow fleas produce their own type of antifreeze, a protein that is rich in the amino acid glycine. Glycine prevents the formation and enlargement of ice crystals, enabling these creatures to keep on munching organic materials despite the bitter cold. You’ll see them on warmer days when the snow melts because snow fleas are rising to the surface of the snow in search of new food sources.

Because snow fleas live in areas rich in organic materials (like leaf litter), they are quite common around tree trunks. Snow fleas are small, about two to three millimeters in length, and they are blue-black in color.

While they look a lot like biting, parasitic fleas, snow fleas are not something to fear. They won’t bite and they are actually great for your lawn and gardens because of the work that they do to help decompose organic material.

Should you happen to spot these tiny hexapods this winter, take it as a good sign that the ecosystem in your yard is healthy and rich in plant matter.

Photo of snow fleas by Photographer Chris Crowley
“The photo of the snow fleas was taken in the yard here in Orford, NH, using a macro lens with up to 5x magnification. They were cavorting on top of the snow during a spring thaw in mid-January.”

Amber Kanuckel is a freelance writer from rural Ohio who loves all things outdoors. She specializes in home, garden, environmental and green living topics. Her article on woolly worm caterpillar folklore appears in the 2020 Farmers' Almanac.

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Jing
Jing
16 days ago

Thank you very much. It is interesting and useful.

Sandi Duncan
Sandi Duncan
10 days ago
Reply to  Jing

Glad you enjoyed the article.

Jenn
Jenn
22 days ago

I wonder how many of these I have ingested since I’ve eaten snow all my life and never knew these things existed. I’m 37…

EC Unhola
EC Unhola
10 months ago

This is the first year I’ve noticed them with snow still on the ground in any visible numbers (good for my yard!) – still I had no idea what they were until I came here… so THANKS!

Eric Patnode
Eric Patnode
11 months ago

That was interesting can’t say I have ever seen them up here in alburgh vt but good information Thk you

Susan Higgins
Susan Higgins
11 months ago
Reply to  Eric Patnode

Thanks, Eric, glad you enjoyed it.