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Snow Fleas Emerging

4-12-19 snow fleas_U1A6604Yesterday was the kind of day when you could not take a step without knowing you were crushing hundreds of Snow Fleas, or Collembola, those tiny black specks on the snow. Their presence is a hopeful sign in northern New England, as it often signals the coming of spring, which we are more than ready for.

This non-insect arthropod is a type of springtail (not a flea). Springtails are no longer considered insects, but are classified as hexapods. These miniscule creatures sometimes come to the surface of the snow on warm winter days but are active year-round in leaf litter, feeding on algae, fungi and decaying organic matter.

Snow Fleas do not bite, nor do they sting. What they do do is catapult themselves impressive distances by means of an appendage on their underside called a furcula which snaps and propels them through the air. They have a soft landing due to three anal sacs that they evert from their anus just before launching themselves. (To see a photograph of these sacs go to a 2012 NC post on Snow Fleas: (Photo: Snow Fleas clustered in the track of a Black Bear that recently emerged from hibernation)

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14 responses

  1. Atha, Daniel

    Hi Mary,

    I enjoy your posts and am very grateful for your service. I will buy your books.

    Could the critters in your photo here be Hypogastrura, not Collembola?

    Best wishes,


    -:¦:- -:¦:- -:¦:- -:¦:- -:¦:- -:¦:-
    Daniel Atha
    Director of Conservation Outreach,
    Center for Conservation Strategy
    The New York Botanical Garden
    2900 Southern Blvd., Bronx, NY 10458
    Office: 718-817-8896 | Mobile 718-514-3922

    April 12, 2019 at 8:18 am

    • Hi Daniel,
      Yes, my guess would be Hypogastrura nivicola, in the order Collembola.

      April 12, 2019 at 12:25 pm

  2. englishrtcc

    We are fascinated by these creatures! One lingering question – why do they come out when there is still so much snow? Is there a nutrient-rich food source on top of the snow they can’t get from under it? Do they need the sunlight? Thanks, Mary, as always!
    Meredith and David Liben, Hartland

    April 12, 2019 at 9:33 am

    • That is the $64,000 questions, Meredith and David! One theory is that they are looking for new sources of food…but I don’t believe anyone has determined for sure the reason for this behavior.

      April 12, 2019 at 11:20 am

  3. Simply stunning Mary – Collembola in a bear track. In addition to the wonderful natural history that your relate, you are so creative, and so often make my day – thank you!

    April 12, 2019 at 10:00 am

  4. Love that you got a photo of them on a bear track!

    April 12, 2019 at 11:21 am

  5. Alice Pratt

    Years ago, when I first saw these on a walk, I had no clue what they were…now with internet availability, it’s just so fun to look things up & attempt to satisfy (my) curiosity…even more fun is having ‘MH’ the naturalist to turn to & who’s blog I love to follow, for more answers. The Bear Print is awesome!

    April 12, 2019 at 3:30 pm

    • Thank you so much, Alice. Your words warmed my heart!

      April 12, 2019 at 3:54 pm

      • Alice Pratt

        🥰☺️ It’s so true, Mary, & you know it! You are a very special person to so many! What a great way to live!

        April 12, 2019 at 8:44 pm

  6. Bill on the hill

    Interesting why these creatures are not classified insects. So, in layman’s terms, they blow a series of farts just prior to touchdown… ” Houston we have landed! ” LOL…
    The photograph is priceless Mary.
    Bill… :~)

    April 13, 2019 at 8:49 am

    • Peter Hollinger

      One reason they’re not considered insects is that they split off before insects developed wings (but after the hexapod line developed six legs). So the ancestors of springtails never had wings, whereas ancestors of wingless insects like fleas did once have wings.

      April 15, 2019 at 11:52 am

  7. Dianne Wright

    Maybe you can find some snow “fleas” on patches of snow. They are t really fleas, they don’t bite or sting.

    Sent from my iPad


    April 13, 2019 at 4:21 pm

  8. Lynn

    Hi are you still posting to your blog site Mary?

    November 7, 2019 at 10:48 am

    • Yes I am, Lynn. Just go to the blog and click on “Sign Me Up!” and you’ll get them as emails three times a week!

      November 7, 2019 at 11:09 am

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