I had a terrible ant problem so got ant exterminator guy over had a look around said i have 2 options. Option 1 set bait stations up outside where he can see them coming in or put this stuff in my roof in water and basically gases them , goes through whole roof only need to be out of the place for couple of hours ( take any pets with you) it started pretty much within a day the ants falling from ceiling and walls etc was horrible looking. if you have a lot of ants can be a little messy but easy vacuum up really. After a couple of weeks ALL ants gone. Never come back since! Totally worth it!