I have two rescued cats and a stray that adopted us, and have never had an issue with the chickens, guineas, or our new ducks. They will hang out with the chickens in the coop, under the shed when it's hot, even laying in the nests! They did not even bother them when they were babies. They would lay on top of the brooders and watch them, but never made any attempt to kill them. The cats are all very good ratters, and will kill wild birds, rabbits, lizards, etc., but I completely trust them with the poultry.