Aussie Hunting and Killing Animals

Does anyone have an Aussie that hunts and kills animals in their territory? She has killed a lot of small animals. Recently my Aussie has been killing feral cats. I found her laying next to a cat with it's face missing. She has also killed a litter of kittens and ate them (later puked them up, that's how I knew). This behavior is very upsetting to me. Otherwise she is a very loving dog to her humans.