They're tiny little critters. One bit me on the wrist about two weeks ago while I was out working on my lawn...I still have a tiny scab, but for a few days afterwards, I had a rash and swelling about half way up the bottom of my forearm, and up over the back of my thumb. Another one bit me on the ankle and left a similar welt. They don't seem to have been bothering my dog, a long, thick haired Tervuren, too much, but my girlfriend's dog, a short haired boxer has left my yard with some pretty nasty bites.
I notice them most around the front gate of my privacy fence but haven't quite pinpointed the nest yet. I think it's time for a curing fire.
Also both my dogs have been bitten by something that they are very allergic to but Vet and I determined it's not fleas. This may be it. (Not this variety but fire ants.) They might have plopped down on a mound or something.