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Mystery Basement Beetle - Tenebrio obscurus

Mystery Basement Beetle - Tenebrio obscurus
Denver, Denver County, Colorado, USA
June 30, 2019
Size: 1.5 - 2 cm
We have some sort of infestation of these guys in our basement. They collect under the cat's litter box and in other dark areas. They seem to be light phobic because I usually only see them at night or if I go looking under and behind things. I have sometimes seen some wormy looking things in the area and I wonder if these are the larvae? They tend to flip on their backs and have difficulty righting themselves - their little legs will wiggle wildly as they try to flip back over. I find a bunch of dead ones laying around, and some even try to climb the stairs. Don't know if they're trying to get out or what. They move fairly slowly, so they're pretty easy to scoop up and dump outside but every day we've got a good dozen more under the litter box. Any help identifying them and/or suggestions for getting rid of them would be greatly appreciated!

Moved from ID Request.

= "lover of darkness".

This looks like Tenebrio; one of the mealworms. I've not heard of them becoming a pest, but if there is anything that they can feed on its a good possibility. The "wormy things" may likely be the larvae - they would look like pet store mealworms.

Thank You!
Thank you so much for your reply! It sounds like a good fit, and much less horrifying than the powder post beetle that I thought they might be. We use a type of cat litter made from wheat, and I'm wondering if they're feeding on that and/or if they arrived as eggs in a some of the litter. I think I'll try dumping all of our current litter, doing a thorough clean up, and start with a fresh bag & see if that helps. I really appreciate your help!

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