Well, they don't have to kill them to challenge them or chase them off. Our cats at home will (and have all) taken on coons in our backyard before. They sound like screaming children when they fight, it always wakes us up. So far, there hasn't been a coon that's won the fight- but there's not been deaths on either side, so I assume the coons take off because it's not worth it to fight the cats. Three of ours don't even have claws and they still have at it... but our cats are pretty big, I think our smallest is 12lbs.