What other pets should be avoided if you have a cat?

Cats generally go after small prey, typicaly mice. Squirels are about the biggest prey they might catch, though some large cats have been known to bring home small rabbits. I think most cats are smart enough to figure the odds and go after prey that won't likely fight back. I have a healthy respect for what a parot's beak could do to me, and I'm a LOT bigger than it. A cat's hunting instincts are triggered by rapid horizontal movement or by fluttering movement. A bird like most parots that holds it's ground is going to make a cat stop and study the situation, and perhaps test the waters with a paw to see what the bird will do. Still, I would not leave a cat and a bird unsupervised. Smaller birds would defenitly be fair game for a cat.