do they have a purpose?? other than to make me miserable?

I went out to check the mail, barefoot, like I always do, didn’t pay much attention… till I have been bitten, I look down and the sidewalk is covered in fire ants. They weren’t there a couple hours ago. I managed to get 4 bites on one foot before I got out of the middle of the invasion, and got them all off me.  And of course, there is no ant killer in the house… My foot is driving me out of my mind  trying not to rub it, cause, I know that will only make it worse. This may require chocolate.