A lady staying in a hotel kept a pet parrot who she would often let out of the cage to fly around the room. One day, the lady was about to leave to do some errands, but had forgotten to check whether she had closed the parrot's cage door or not; because she was in a hurry and didn't have time to go back, she quickly wrote up a note, reading, "Please enter with care, Pet flies!" and taped it to the door.

By the end of the day, the cleaning lady went to meet with the hotel manager. "Have you cleaned all of the rooms?" he asked.

"Yes," she replied. "All except for the room of that one tenant with the pet flies."