A man with two buckets of fish was just leaving a lake, was stopped by a game warden who was checking the area for people fishing without a license. 

The game warden asked the man, “Do you have a license to catch those fish?”

The man replied to the game warden, “No, sir. These are my pet fish.”

“Pet fish?” the warden replied.

“Yes, sir. Every night I take these here fish down to the lake and let them swim around for a while. I whistle and they jump back into their buckets, and I take ’em home.”

“That’s a bunch of hooey! Fish can’t do that!”

The man looked at the game warden for a moment, and then said, “Here, I’ll show you. It really works.”

“O.K. I’ve GOT to see this!” The game warden was curious now.

The man poured the fish in to the lake and stood and waited. After several minutes, the game warden turned to the man and said: “Well?”

“Well, What?” the man responded.

“When are you going to call them back?” the game warden prompted.

“Call who back?” the man asked.

“The FISH.”

“What fish?” the man asked.