These cats kill them when they get the chance.
Pen up the chickens, or get rid of some cats. Personally, I never had a cat kill my chickens, but if I did he would be gone in a heartbeat. My chickens feed me, that cat is an extra. Since, you posted this question, I am thinking you aren't the kind to take a shotgun to the cats, so if they are strays you can try walk in/release traps, or call the human society and see if they can catch the cats, or have any suggestions.
Though I have had many cats think they were going to toy with my chickens, get attacked by my birds, I still believe that when push comes to shove, a chicken is no match for a cat.
Sorry about your flock, and hope it all works out,
Jamie/Rhoderunner
We have a farm, and none of our cats (in their right mind) would ever go after a chick. The moms, both ducks and chickens will chase the cats away. Unfortunately, the weakest do get caught, but that is just how it is. Survival of the fittest ...
It is always sad, but there is nothing you can do to stop a cat from hunting.
pets question and answers,www.5d2d.com If your cat hunts a regular adult chicken, then it has some ******. Ducks are worse, as they are much bigger and won't put up with that kind of behavior.
Cats look for the old, weak, or injured animal.
The only thing you can do is pen old, injured or weak chicks, ducklings etc.
Cats do what they do.
Poison some sardines and leave them around, but make sure the chickens don't get to them