Cats are no fools.
Several years ago the cat was apparently intent on teaching me to hunt. I was on the phone and not paying attention as she scratched at the door. Walking over and talking I let her in without looking down. I realized she was standing in an awkward stance but paid no attention. Finally, I disconnected and looked down at her. She had her foot pressed down on the tail of a struggling rodent. The moment she saw she had my attention, she lifted her foot and it took off running. I threw the phone down and lunged. She kept up with me and when I had it cornered she looked at me and slapped both her front paws down on the carpet, I assume encouraging me to lunge. It took about 30 minutes to catch the thing and take it outside. She seemed very self-satisfied. Once she came in with something in her mouth. When she had my attention she opened her mouth and out hopped a frog, completely unhurt. It was slightly easier to catch, but still hugely entertaining to my feline companion.
(Incidentally, this is why I no longer have a kitty door. She gets inspected prior to entry.)