What -if any- poison can I use to get rid of the red biting ants in my yard. They are everywhere!! I have used the food grade DE but that isn't enough. I have 30 hens and they free range during the day. Not sure if I trust the pest control co. as they tell me it's safe after it drys. But the hens pick thru EVERYTHING and stuff gets rinsed off and rain happens... Thank you.