best thing I have found for sugar ants is made by Terro, called sweet ant bait. Kind of like Kayro syrup, really messy if spilled. You put a small amount in a bottle cap, place near their travel path, leave for a few days, and they disappear. If you spray them, they will come back by another path(and you have to clean up a bunch of dead ants), according to the exterminator who told me about this stuff. Yes, they seem to be an indicator of heavy rain, as well as spiders around my house. I never see spiders (inside) unless we have a period of rain coming. As far as fire ants, the best thing I have found(although poison) is Orthene powder. You don't have to water it in, just sprinkle a teaspoon full on the mound and leave it. They will be gone tommorrow, however they will move to another part of the yard but if we are talking about my yard,they are probably already there. Works much better than the granules you have to water in.