They really are smart.... predators have to be. Weez really learned alot from playing with me. Honed her reflexes. She wasn't outside a week, when she caught her first chipmunk. She doesn't kill anything yet unless it dies of fright! (the pigmy shrews do die of fright)...
Nor does she try to eat them. Oreo DOES eat her kills most of the time if hungry. Or she leaves them for us, dead.

I've watched them stalk a chipmunk hole together. In fact I've seen Oreo bring a live chipmunk to Weez to teach her!

I think cats who do not go outside have to have an outlet for their instincts. Some may be hunting or mothering.
Sheba used to play with our son's giant rubber ant toy. She'd bite a leg then throw it up in the air and pounce on it! But I don't recall her ever trying to catch a living thing even though she went outside. It must be somewhat unique to each animal based on their needs and cravings etc.

But I agree, fun to watch! In fact here, it is never a dull moment some days! LOL