I read this joke on Reddit a few weeks ago and got a real kick out of it
One day the Game Warden came across a man near a creek with a bucket full of fish.
GW: Excuse me sir, can I see your fishing license?
Man: My fishing license? I don't think you understand. I didn't catch these fish. They are my pets. I take them for a walk down to the creek each evening and let them swim for a bit before taking them back home.
GW: Yeah right...
Man: I'm serious, here I'll show you.
The man proceeds to dump the bucket of fish into the creek and waits.
After a few minutes...
GW: Well?
Man: Well what?
GW: Your fish... What's up with them?
Man: I don't know what you're talking about. I don't have any fish.
The man picks up his empty bucket and walks away leaving the Game Warden wondering what just happened.