Just because you don't see them doesn't mean they aren't there. They're just not making mounds because of the heat and drought. They will resume mound building as soon as the area receives significant rainfall. Fire ants are often more of an indoor problem at these times because they come in after food and water. Treating now can be very effective since the colonies are weakened anyway. Individual mound treatments, particularly with contact insecticides, are less effective during hot, dry conditions because the colony is not near the surface. However, because the ants must come out of the ground to find food and water, baits can work quite well. They should be applied in the late afternoon or evening when there are no thunderstorms predicted and there is no dew on the grass. The late application time will keep the bait from spoiling in the sun. Most of the bait will be picked up by ants foraging at night.