I use the poison in bait stations. Nothing but rats and mice can get to the bait. Like Mary I had a coop that was infested. I had nests in the ceiling and walls of the coop. When I tore out the ceiling and walls, dozens of rats of all sizes poured out. I put the bait stations in our barn which is behind the coops. There is a little window above the bait so it can be checked frequently and replaced as needed. I tried a few other things but I was still seeing rats so I resorted to the poison in the bait stations. There is a partition in the middle of the bait box that the rats have to go around to get to the bait.