...Hmm. Sounds like some variant of a 'fire ant'. Your county/parish 'Ag. Agent' (if you have such a thing) may be able to tell you what they are, or any of the other suggestions given. Best advice is to leave them alone (LOL)!
Something that works here is to distribute 'horse apples' (the big green thingys, "fruit" from a "bo-dark" tree, I can't spell the name, sorry), around where they nest. Won't kill them but does make them move to a different place. Intimate contact between ant and the head of a hammer works too...
- 'Doc

PS - 'T.Bob', it's called anaphylactic shock, depends on how 'allergic' a person is to the venum, and can be ~very~ 'bad'. Same as someone being allergic to bee stings, etc. Having a 'cow' doesn't begin to describe how it feels...