Great pics - thanks for sharing!!
Fire ants - while it was good for you to have the 'experience' of fire ant anger - for the 'real' experience, you've got to accidentally stand in one of their piles and casually have a conversation w/ one of your friends. By the time one of them decides to sting you, it will have a few hundred / thousand of it's buddies in close proximity. When one stings, it sends a message to all of the others to get busy and do the same. That is the true fire ant experience! Now, go back & do it the right way!
Also, you might want to check the ID on your S. alata, I suspect that it is S. rubra ssp. rubra ...