If there's a classic example of predators and prey, it's cats and birds.
Our feline friends really love to hunt down anything with feathers. They view bird as their natural enemies, with outdoor cats killing millions of birds every year. Our indoor kitties get to indulge their predatory instincts by watching out the window, and they sure can get excited.
That's the case for Charlie, who loves to sit and "hunt." I don't know how successful he would be outside, though, because he does something that's both strange and cute.