Fishing Without a License
A man is walking from the lake carrying two fish in a bucket. He is approached by the Game Warden who asks him for his fishing license.
The fisherman says to the warden, "I did not catch these fish, they are my pets. Everyday I come down to the water and whistle and these fish jump out and I take around to see the sights only to return them at the end of the day."
The warden, not believing him, reminds him that it is illegal to fish without a license. The fisherman turns to the warden and says, "If you don't believe me then watch," as he throws the fish back into the water.
The warden says, "Now whistle to your fish and show me that they will come out of the water."
The fisherman turns to the warden and says, "What fish?"