Serving Northern St. Louis County, Minnesota

The season of snow fleas

Watch for these common organisms on mild late winter days

Marshall Helmberger
Posted 3/18/20

They appear, seemingly like magic, on mild winter days— looking like flecks of pepper on the snow. And unless you look closely you might not realize they’re alive.They’re commonly …

This item is available in full to subscribers.

Please log in to continue

Log in

The season of snow fleas

Watch for these common organisms on mild late winter days

Posted

They appear, seemingly like magic, on mild winter days— looking like flecks of pepper on the snow. And unless you look closely you might not realize they’re alive.
They’re commonly called “snow fleas” and March is perhaps the best time of year to take a closer look at these tiny creatures that manage to survive even in sub-freezing temperatures. The term snow flea is applied to any number of small organisms that can appear in large numbers on the surface of snow. The type of snow fleas found in northern Minnesota aren’t true fleas— in fact, they aren’t even insects. Instead, they’re a common soil invertebrate known as a “springtail.” They’re dark gray in color and live most of the time in the forest floor duff, where they feed primarily on fungi and decaying organic matter. They’re so small, measuring barely a millimeter in length, that we hardly ever notice them at other times of the year.
But during the winter, when they take advantage of milder days to pop up out of the snow, their dark bodies, especially when they accumulate in large numbers, stand out against the backdrop of white. They come to feed on algae, fungi, and other bits of debris and dust that accumulate on top of the snow and then they disappear back under the snow when the real cold returns.
Our snow fleas can’t fly, but as their name suggests, these springtails are able to jump, flea-like, many times their body length through the use of a tail-like appendage. And they hop a lot. If you stop and watch a concentration of these snow fleas, you’ll see these little springtails are leaping about almost continuously. We’ve posted a video of them online at timberjay.com so you can see them in action.
These snow fleas are one of the few very small organisms that remain active during the winter months. They have glycine in their bodies, which acts like a natural form of antifreeze that allows them to function even when temperatures are below freezing.
With milder weather ahead, keep an eye out for snow fleas over the next few weeks. Once the snow is gone, they’ll still be there— you just won’t be able to find them.

Comments

1 comment on this story | Please log in to comment by clicking here
Please log in or register to add your comment
Snowshoe2

I haven't seen any yet some years I can fill a quart jar full from a little depression they fall into.

Saturday, March 21