Looks like envenomation to me. You should have seen the big purple bruise on my thumb that time Cee Cee decided she was a rattlesnake and jumped across the tank and struck me really hard. In the book I was talking about, the author said that the person who was bitten by the garter was bitten several times over a period of time before the systemic reaction occurred. It was also a child. But, it makes it sound as though our bodies hold the venom somehow.