Later I read of a pet octopus who developed another way to signal that she wanted the owner’s attention. If the person was out of the room, the octopus would pull off the magnet on the inside of the tank which, with another magnet on the outside of the tank, held a glass-cleaning tool in place. The outside magnet would then crash loudly to the ground, summoning the human much as one might call a butler by ringing a servant’s bell.
