I've successfully "taken care of" 15 ant colonys in the yard! They've been getting out of hand recently, and I needed to do something about it. Two of them were right by a nice tree and were destroying it. I'm on 2 acres, and was hitting a friggen ant pile every 2-3 passes with the mower, and decided it was time to do something about it. Some of the ant hills out in the 300acres behind me (all field/forests) are chest high, those buggers no how to build! I decided against chemicals because of the 5 year old and our pet. What I found to be extremely effective though was, get this: water. Fill a 5 gallon bucket, pour it on the colony. Repeat 2-3 times a/day for 3-4 days. Colony gone. Some were destroyed the first day. But I just wanted to make sure. I tried the hose on 1 first, it's too slow, I found too many ants were able to esacpe and the male winged ants would be able to come up and get away, and the female workers would be bringing up all the larvea and stashing them out of the target zone. 5gallons at once though, and they've got no chance. A quick reconnaissance mission today, 3 days after I last "treated", no activity at any of the 15 treated colonys, just a small "ground zero" depresison where the earth had sunk back down.