We were down in Darlington at the race track and overnight we were invaded by fire ants. I have always just sprayed around the outside of it were it sits but had never sprayed the inside. I use Ortho liquid spray that you can get at Lowes. It comes in a gallon jug with its own pump. I started to spray the inside of the compartments and under cabinets when I spray the garage. Every 6 months and we have never had bug issues inside again. It doesn't take much!