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Entomology (Study of Bugs)/Unknown bug in bedroom


Unknown Pennsylvania Bug
Unknown Pennsylvania B  
I recently returned to Pennsylvania and am staying in my childhood bedroom which is not typically used. Since being home, I've noticed a number of bugs (all the same kind) in my bedroom. They are very adept at both crawling and flying, and they don't seem to fear humans very much.

They seem especially attracted to the light affixed to my ceiling fan and although I caught all the ones I could, after leaving the light on with no windows open more were able to come from somewhere. They don't seem to be in any other rooms of the house. I am also wondering if they could be coming through the ceiling fan down into the room, as I closed the other vents and windows after removing them the first time.

Thank you in advance for your help!

Dear Monica - If the other insects you are seeing in the room are the same as this one, you have nothing to worry about. It is a ground beetle (Coleoptera: Carabidae), and ones like yours are general predators on other small invertebrates, mainly other insects, and thus often considered beneficial.

Hope this helps,

Entomology (Study of Bugs)

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Ed Saugstad


Will accept most questions in general entomology, including those related to medical entomology, taxonomy, ecology, arthropod surveillance, and pest management. If you are requesting a 'mystery bug' identification, PLEASE either attach an image to your question, or post an image on a web page (such as Flickr) so that I can look at it, as verbal descriptions frequently are insufficient for a definitive identification.


21 years in the U.S. Army as a medical entomologist; duties varied from surveillance of pest populations (including mosquitoes, cockroaches, ticks, and stored products pests) to conducting research on mosquito-virus ecological relationships and mosquito faunal studies. Ten years as a civilian analyst for the Department of Defense, primarily on distribution of vector-borne diseases worldwide. Limited experience on surveillance of agricultural insects in North Dakota and Indiana.

Entomological Society of America, West Virginia Entomological Society, Society for Vector Ecology, National Speleological Society, West Virginia Association for Cave Studies.

American Journal of Public Health, Contributions of the American Entomological Institute, Japanese Journal of Sanitary Zoology, Journal of Economic Entomology, Mosquito News, and Mosquito Systematics.

B.S. in entomology from North Dakota State University in 1963, M.S. in entomology from Purdue University in 1967.

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