a business card or like weight/sized peice of paper in the middle of it, place a spoonful of DARK molasses Sprinkle DRY granular yeast over that place it where ever you find ant trails. What happens: the ants are after the molasses, and take the grains of yeast back to the nest. The ants eat. The yeast starts working, and they blow up. When my children were young, convinced them that if they put their ear to the ground and were very, very quiet, they'd hear them explode.