Entomology (Study of Bugs)/worms


QUESTION: In the last few weeks, we have had an infestation of some type of worms in our outside patio area. The in- ground pool is polluted with them! They are all over the solar cover, the sides of the pool wall, and millions are dead in the water. They are crawling up our aluminum siding walls of our house. They are everywhere in our patio, but mostly in the pool. They seem to be breeding in clumps of wet areas of the solar cover. They are dark brown, and about an inch long. I live in Hanover, Pa. They are out all the time! and so GROSS!  Please help me!!!

ANSWER: Darlene:

Good thing you included an image because I would not have been able to identify whether it was even an arthropod you were talking about....

The creature in the image is a "Greenhouse Millipede," an introduced species to the U.S. :


For more information I would "Google" the scientific name and use ".edu" website search results.

Millipedes are generally scavengers on decaying organic matter.  The ones in your pool fell in there and drowned.  Millipedes do not pose any health threat and rarely damage live plants.

Oh, and millipedes are not insects, or even arachnids.  They are in a class by themselves:  Diplopoda.


---------- FOLLOW-UP ----------

QUESTION: Thanks Eric, but how do I get rid of them?!!!  I don't have any food around the pool for them! We are not in a drought, so I don't think they are thirsty! HELP!!!  They are ruining my pool parties!!  Thanks! Darlene



I am not in the business of offering control options.  My goal is to generate appreciation and tolerance of insects, spiders, and other arthropods.

Here is more information that includes control measures, as offered on the sources I suggested in my last response:




Good luck.


Entomology (Study of Bugs)

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Eric R. Eaton


I answer insect and spider identification questions ONLY. Attach images if possible. No "what bit me?", "what do I feed this bug in captivity?", or science fair project questions please. NO TECHNICAL QUESTIONS ABOUT INSECT PHYSIOLOGY.


Principal author, Kaufman Field Guide to Insects of North America. Professional entomologist employed previously at University of Massachusetts, Chase Studio, Inc., and Cincinnati Zoo; contract work for West Virginia Department of Natural Resources, Smithsonian Institution, and Portland (Oregon) State University.

Author, Kaufman Field Guide to Insects of North America, Missouri Conservationist magazine, Ranger Rick, Birds & Blooms, Timeline (journal of the Ohio Historical Society). I have contributed to several books as well.

Oregon State University, undergraduate major in entomology, did not receive degree.

Awards and Honors
One of the top 50 experts in all categories for AllExperts.com, 2009.

Past/Present Clients
Principal author of the Kaufman Field Guide to Insects of North America, Smithsonian Institution (contract), Cincinnati Zoo (employer), Portland State University (contract), Chase Studio, Inc (employer), Arkansas Museum of Discovery (guest speaker). Currently seeking speaking engagements, leadership roles at nature festivals, workshops, and ecotours.

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