The first time I saw these was in an old cooler full of water by my shed, there were 3 of them about 2 weeks ago. Now tonight I found one crawling up my door. Can anyone offer some insight? I have dogs and I'm horrified that it may be some kind of parasitic worm that they can contract.

This was observed in northwestern Pennsylvania, US. Rainy, cool fall weather currently, as it's the end of October. They're about 2 inches long. Very thin, blackish red in color and extra wiggly.

it's looking where to go, I had just poked it and he didn't like it

close up of him stretched out the darker end appeared to be his head area. That's the only direction it moved in

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    $\begingroup$ Have you never before seen an earthworm? $\endgroup$
    – Roland
    Commented Oct 30, 2020 at 7:23
  • $\begingroup$ Yes, an earth worm has that bump thing on it. They're generally fatter. $\endgroup$
    – amber
    Commented Oct 30, 2020 at 9:33
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    $\begingroup$ There are several species of earthworms. For some of them the "bump" is less pronounced and some are slimmer. Everything you report (occurrence after heavy rain) fits earthworms. The picture looks like one too. But photo quality isn't sufficient to be 100 % sure. $\endgroup$
    – Roland
    Commented Oct 30, 2020 at 11:27

1 Answer 1


The "bump" on an earthworm (i.e., a worm species of the order Opisthopora) is a clitellum. Clitella are only visible on earthworms when they're sexually mature [Sources: 1, 2, 3]. So the absence of a clitellum does not preclude your specimen from being a member of this order.

The species in your photo is almost undoubtedly some species of earthworm. Without clearer images or more detail, I can't imagine someone taking the time to try to ID to species.

There are many species of earthworms present in Pennsylvania (though likely none of them are native to the US: see here). Keep an eye out for a recent invader, the "Asian Jumping Worm" [read more].


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