Eeeek! I have fire ants!!!

It was wonderful to be greeted by such nice and helpful TV friends, but I could have lived without being greeted by fire ants in the yard!

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My biggest concern is they will bite my babies, and they love to go out and play.
Bernie suggested a powder and Nonie is taking me today to get it. Is there anything else I need to know or do so they will go away pronto? How long do these nasty things visit us? Do I do the whole lawn and trees etc.?
Last question hehe....do I just hire someone or is it very costly? I dont mind doing it at all but was wondering how it is on the lungs?

Appreciate any advice...thanks!
JeanneBeannie