Entomology (Study of Bugs)/Tiny Black Bug


QUESTION: Central Montana, near Great Falls. 8/13/2014, roughly 10:30am mountain time.

The little bug in question is almost oval, with the head area being slightly larger than the rear. The beetle/bug is not segmented, as far as i can tell... just one little almost perfect oval. It is primarily black, with some sort of pattern on the back, either in orange or yellow (under bright light). It is about 1.5/16th of an inch long, if I'm measuring right. It also doesn't appear to have any obvious antenna. Moves by crawling fairly slowly, spends a lot of time immobile.

This particular bug was on my bed, but I have seen them (or similar bugs) all over the house at various times over the years. My house is easily accessible to lots of things, so it could just as easily be an outdoor species that has wandered in. I have never seen more than one at a time, that I can recall. Time between sightings is often a month or more.

I don't have the means to get an image, however I do have the little guy trapped in a cup next to me.

Not really terribly concerned over it, just got a little curious after finding this one in my bed. All I could really determine is that it probably isn't a bedbug.

Much appreciate a response, thank you in advance.

ANSWER: Jeremy:

Unfortunately, your description fits literally hundreds, if not thousands, of insects.  It could even be a larva of some kind, or a crustacean like a woodlouse.  Maybe it resembles one of these:




The Larder Beetle (last link above) would actually be a good bet as they are very common in the Rocky Mountain states, infesting all manner of dried animal products.

Hope one of the above is the solution.


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

QUESTION: I appreciate the fast response, thank you.

The body shape of mine looks fairly similar to the fourth picture in the first link, but is missing any of the orange/yellow design. I also didn't notice any of the obvious ridges you can see going across the body in that picture.

The orange/yellow design is composed of small, thin lines.. nothing at all like the thick band in the last link. That last link is also far too long (proportionally).. my guy is only slightly less fat than he is long.

The design itself actually looks similar to the pretty common eastern boxelder bug that I remember from back home. Except a fatter, much less elongated version of it.
If you took the body structure from
and color/design from
it might be somewhat close.


I still suspect some kind of dermestid.  Try browsing these images:


Carpet beetles make much more sense than boxelder bugs or any other true bug at this time of the year.  Come fall, yes, several kinds of true bugs seek shelter indoors.

This is the most I can do for you without seeing at least an image of your insect.  Thank you for understanding the limits of what I can do without more evidence.


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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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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