Put a box on the floor and a cat will likely jump inside. Yet if you create a square on the floor using nothing but ordinary masking tape, cats will often jump inside this square as well, despite the lack of protective walls around them.
Animal behaviorists then wondered if cats would be tricked by optical illusions that mimic squares, such as four PacMan-like objects on the floor that form a square. Amazingly, cats did fall for this illusion. If you think cats are less than intelligent for getting tricked so easily, all you have to do is look at who many people vote for in every election to realize that people are still dumber than most animals.