Problem there is you assume animals behave worse than humans. Only humans "rationALIZE" enough to ALLOW bad behavior! Sometimes we can learn from the natural animals - they don't think twice about discipline - yes, teeth, hooves, and other physical stuff! Why should we? (And that applies to raising animals in a human world, too!)
My cat Cassie is a perfect example. Bailey, my dog, likes to indulge in 'playtime' with Cassie and Cassie usually likes to claw at the dog to keep Bailey away. That brat of a dog still thinks that Cassie is just the perfect playmate.