i'm pretty sure they were coons that got mine... they pulled chicks thru 1" welded wire. the cats' paws are bigger than that.
If you've got your chickens in pens, that's the classic finding when raccoons are your predator -- heads or feet or wings or chicks pulled through wire that you thought was protective. A friend of mine had a serious raccoon problem before I got my first chickens, and told me to attach 1/2" hardware cloth to any wire were a chicken could be within reach of a raccoon. So far it's worked great, and I've got lots of raccoons on the property.
I've never had a problem with cats killing my chickens, but if you've got timid chickens and really confident cats I guess it could happen. I introduce my chicks to my cats when the chicks are 4-5 weeks old. My cats are very aggressive hunters, but they also understand a firm "NO!" So as they stalk a few chicks they are told to stop, and as they do the chicks become quite confident. After a week the chicks are starting to flare their hackles or flap their wings and as they do that the cats get startled are back away. The chicks are then confident and pretty soon are chasing the cats all over, with encouragement from me. Once they're doing that, they are allowed into a dog/coyote proof area, but there are several stray cats that do wonder in. The chicks thinks of them as prey, and confidently chase them en masse, and those cats run. Now, admittedly, the chicks have been intentionally set up for success. I have no doubt that any cat could kill the chicks, and that a good feline hunter could even kill an adult rooster. But this technique has worked quite well for me so far, just by taking advantage of the natural behavior of each species and working to enhance it. I do not think, however, that it would be effective at night, if chicks are not adequately protected during that time, when any cat would have a huge advantage against even a large bird.
Thank you, dncarr09, for finding a humane solution to your situation. I would do anything to protect my chickens, but I have to admit that your original post made me a bit uncomfortable. Thank you for the full explanation