Yeah, but they're not working FOR you. They're doing it because they like to. And yeah, herding dogs love to herd, and hunting dogs love to hunt, etc., but dogs by their very nature are always trying to please you, even when they're doing what they love to do. They wiggle out of their skin if they make you happy. But cats? Find some way to tell a barn cat that he's doing you a favor by killing rodents, and I guarantee he'll stop killing rodents.