As a cat lover that keeps mine INDOORS for multiple reasons....I can tell you, cats are very territorial. My neighbor has cats that stay outside and two consider MY yard, their yard. Cats are curious, and are only domestic creatures able to go feral if left alone. If you get a large dog, the cats may go away as the dog will bark or chase them. Cats do not like lemon/citrus scents -at least inside-hence why I place lemon scented deodorizers near furniture I want to keep them away from. Some cats are repelled by aluminum foil-the feel of it bothers them. Of course the best way to deter an unwanted kitty is water--do you have a water gun ?? Not sure if they have motion sense water sprinklers, but if they do put them round the coop/run or rig some thing is the best I can offer. Hope this helps!!!! Pity you cant teach the chickens to squirt water guns at the cats-what a sight that would be! LOL!!!