I have read on here that some people have a problem with fire ants. A spot treatment I have used to good effect is bleach and amonioa, this is the how .On a 12" mound pour 1/4 cup bleach wait 30 seconds then pour 1/4 cup amonioa . It will degrade to salt water. Do not mix the two as you want the chemical reaction to happen under the ground and not in your container. It will not hurt your chickens . It makes a poisonous gas,then degrades to salt water. It may temporarily kill the grass. In some cases you may need to do it twice. Do not disturb the nest , just get as much of the top wet,as you can. On smaller mounds you can use less. I have used a spray bottle in order to disturb the nest less. Hope this helps.