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Entomology (Study of Bugs)/flying insect identification- follow-up


top view of insect in container
top view of insect in  

side view of insect in container
side view of insect in  
Hi Eric,

A few weeks ago, I mentioned my daughter was hearing a buzzing in the walls of her bedroom. We live near Detroit in Michigan.

Today around 11am, she found what looks like a wasp in her bedroom. It was flying towards the windows trying to find a way outside. All windows were closed and have screens on them. She did not see how it entered the room.

A few days ago, we found one of these on the floor of our kitchen. Both times the insect was rather easy to trap.

I have also been bothered by this same type of insect when I am outside near the house. I have swatted them away and they leave.

If this is the type of insect in the wall-
Can it damage the house?
Are they dangerous?

Thank you,

Hi, Bruna:

The insect in your images is a solitary wasp known as the Blue Mud Dauber, Chalybion californicum .  Here is my blog post about them:

That *should* answer all your questions.  It is likely they have been refurbishing nests of the Black & Yellow Mud Dauber, Sceliphron caementarium , in your attic or walls.  Since they are not social, the nests are small and the wasps non-aggressive.  I would not be concerned.

Thank you for continuing to catch-and-release these wasps.  They hunt spiders and are an important part of the outdoor ecosystem.  Sometimes our human habitations simply offer the most attractive places for them to nest.


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, 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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