What's so cool about flying in squares?

July 8, 2011 4:21 PM

vacapinta asked this way back in 2004 but the answers provided did not satiate my curiosity so I'm asking it again: What are these circling (or squaring) flies? I live in San Francisco but I saw them when I lived in Southern California too. I don't have a pressing reason I need the information, I'm just curious as all get-out about them.

I'm not an entomologist but I'm pretty confident that they're Musca and not Drosophila (mostly because of their size). I'd be happy for just a species name, but if anyone has personal knowledge about them that would be wonderful.

posted by dolface to science & nature (3 answers total)

I observed them during my 1976 trip to San Francisco, but haven't seen them since, either in NorCal or SoCal. In fact they were one of the many attributes of California confirming my impression that the Golden State was a superior place, to which I had to move (although I wasn't able to successfully effect that transition until eleven years later). Such well-behaved, submissive insects, so easy to terminate, so unlike their more aggressive cousins I knew too well, back east. In fact, once here I discovered there were hardly any annoying flying insects, nor any roaches -- only pests I've encountered have been fleas (when I had cats) or Argentine ants. (However, my buddy in the Mission reports having problems with mosquitoes.)
posted by Rash at 5:10 PM on July 8, 2011

I have only a tiny piece of info for you: these are to be found in southeast England as well. For me, their little angular flight paths and grouping in my flat signified the beginning of warm weather.
posted by Specklet at 5:21 PM on July 8, 2011

Every single person I know in San Francisco calls them "Fruit flies".
I have no idea of they actually are fruit flies, but if you call them that in SF everyone will know what you're talking about.
posted by Ookseer at 8:18 PM on July 8, 2011