Cats are easily amused by lasers. By flashing a laser on the floor or wall, you can get your cat to chase it for hours. Of course, that also means you have to stand there, pointing a laser around for hours at a time, so who’s really the silly one in that scenario?
If you want to entertain your cat with lasers but don’t want to stand around pointing a laser yourself, you can build your own cat laser toy. Now you can let a robot play with your cat while you go out and earn more money so you can spend it buying more toys for your cat.