Hi J.,
Yes, it could be something else. Oddly enough, a few weeks ago, I was working in my garden(early morning), had shorts on and felt something on my leg, but continued working and thought nothing more about it. The next morning while taking a shower I noticed 2 very large, swollen, red splotches in the same area where I'd felt "something" the morning before. They neither itched nor hurt and were gone in a few days.
If those splotches were bee stings, I wouldn't be typing this as I'm allergic to bee venom. My guess of what bit your son and me: BLACK FLIES!
For all those who suggested that this might be a TICK bite:
a tick needs to be attached for 24 to 36 hours for a bullseye rash to occur. J. would have seen the tick. She describe a probable Bee Sting, but wasn't positive. This STILL sounds like a BLACK FLY or a HORSE FLY. Both sting quickly and fly off. A bee sting is of much longer duration and hurts like a hot needle; her son would be screaming with pain.
This is just another two cents thrown in to the discussion.