Meet Feline Pythagoras: Maru, the Mathematical Cat From St. Petersburg

Maru is not an average stray cat. He knows how to answer questions about simple arithmetic by ringing a bell.

The owners of the clever cat discovered his rare mathematical talent by accident. Just for fun, somebody decided to ask the kitty, who loved to ring the bell, how much one plus one is, and Maru pressed twice. Since then, with the help of his tamers, Maru has learned how many times to pull the bell and achieved some positive results.