Entomology (Study of Bugs)/What's This Bug???


I live in Denver, PA. Over the past two days (5/31/13 and 6/1/13) I have found three of these bugs in my home. One dead in my bed, one crawling across the bathroom floor (both of these on the second floor of my home), and the last, crawling across the living room on the first floor. We do have a cat that spends a majority of its time outdoors.

Hi, Danielle:

Thank you for including the images with your question, I don't think I would have guessed from a description alone.

The insects are "click beetles" in the family Elateridae, specifically something in the genus Aeolus :


Click beetles are named because they are able to snap a spine into a groove on their underside, a maneuver that can propel the beetle into the air to avoid a predator, or buck the insect out of a predator's grasp.  The beetle may also use the trick to right itself should it fall onto its back.

Click beetles are often attracted to lights at night, and they fly well.  I suspect that is how and why they got indoors.  They pose no threat to people or pets.


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.

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

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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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