In Texas, they just bite your head off. We don't go on walks carrying shotguns to defend ourselves from bears, rabid ducks, and mountain lions...
Umm... you just got so plastered that you passed out for a week.
I use my blood electrifier on each side of a mosquito bite (of which I'm extremely allergic), and it'll knock down the itching for a half day. The electricity really stings, so it probably overloads nerves, kills off whatever the mosquito spit into me, and maybe helps break down some of the chemicals. I don't know why the itch keeps coming back, but it's usually gone after a few days.
You really don't want to find one of these buried. If they're close to your house when they power up and launch, you'll have a lot of damage. It will look more like a sink hole when everything's done. When you tell your neighbors that it really flew up in the air, they'll start asking you about your deer fly bites.
Perhaps you weren't supposed to find something, but to build something? How hard is that limestone to work with? Maybe build a mosoleum to all the dead animals on your property? That way you won't have to give up. If the limestone is layered and can split nicely, grab some mortar and start working on your outside patio, increase your house resale value.