Entomology (Study of Bugs)/Cluster Flies?


I went home today, and found a bunch of flies on one wall in my house. This wall is on a hollow bar in the middle of our home. We live on pier and beam. I live in Central Texas... Dallas area, and saw these today: 6/16/2016 at 12:00 noon.
I googled and got a hit with cluster flies, but it doesn't seem like they'd be around this time of year? could these be blowflies? do blowflies congregate together like this?


Forgive me, but I am not an architecture expert, so I am not understanding your explanation of your home's construction....

The image lacks enough detail for me to conclude anything about the insects depicted.  However, I might have an explanation anyway.

Cluster flies *are* a kind of blow fly, by the way, but I suspect these might be a different kind of blow fly, the kind that exploits animal carcasses.  Perhaps a rodent or other small mammal died in the hollow wall, a fly got to it, laid her eggs, and now you are seeing her adult offspring.  This would not be an unusual scenario.


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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