Pet fish

A man was recently stopped by a game warden in northern Missouri. The fellow carrying two buckets of fish, was leaving a lake well known for its fishing. The game warden asks the man, "Do you have a license to catch those fish? If you don't, I'm going too have to impound them and arrest you." The man replied to the game warden, "No sir. These are my pet fish." "Pet fish?" the warden replied. "Yes sir. Every night I bring these fish down to the lake and let them swim around for a while. Then I whistle and they jump back into their buckets, and we go 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." "OK I've got to see this" (he was really curious now) The man poured the fish into the lake and stood there waiting. "When are you going to call them back?" the warden prompted. "Call who back?" the man asked. "The fish" the warden said. "What fish?" the man asked