My daughter found this chunk of wood, a log with a burl growing out the side. It was old, dry, and starting to rot. I decided to try and make a bowl from it anyway. First got it mounted to a face plate and started turning. Felt like I had something crawling on me, stopped the lathe and found the voids were full of ants and they had flew all over me and the shop and were still crawing out by the dozens. Stuck the shop vac in the voids and sucked out all the ants but still had the heebie jeebies. Got the outside turned and a fairly solid tenon. Turned it over and mounted in chuck. Got down into the bowl and hit huge void with more ants. Discovered the tenon was hanging on to almost nothing at the edge of the void. Got a catch, broke the tenon. Finished sanding inside as well as I could by hand, reversed and jam chucked to finish foot. About 13.5" by 5". Will try to sand the inside better sometime. Still have the heebie jeebies!
And those would, most likely, be Carpenter Ants. I'm quite familiar with the little wretches. They can generate large quantities of sawdust too, during warm weather or indoors. Did you see any with wings?