Our chickens aren't exactly free-range, but they have a large fenced-in area. The fence is electric, and the chickens do go in at night. But when a cat walks by and scares them, they have a tendency to get outside the fence and not know how. And outside the fence... some of the cats would be interested in getting them. And since a big siamese-like cat comes around that will hunt ground hogs, a chicken isn't such an intimidating target.

While I understand that cats are born predators, I can't afford to lose chickens. I wouldn't kill them because they do keep pests down and may belong to someone, but I do want to scare them away from the coop.