Tree Swallows are aggressively protective of their nests and will dive bomb approaching threats. This includes cats, raccoons, and in this case, me. An Apricot tree provided enough cover to get these photos. I had to hold very still as any movement riled up the birds. The mosquitoes were awful which made that torturous as I had to let them bite me.
The Barn swallows I posted earlier feed their young partially digested pellets of insects which they regurgitate into their youngster's throats. Tree swallows differ in that they feed the young whole insects. You can see this in the last photo.