Sailors and cats have had a special relationship for thousands of years. Besides offering sailors companionship on long voyages, cats also rid ships of rats and mice that would eat into the provisions, chew through ropes and spread disease. Superstitious sailors even believed that cats protected them by bringing good luck.

The next time you take a ride on a ship, look for a cat. Chances are good there’s a cat somewhere on board, keeping the sailors happy while performing useful tasks hunting down and catching mice that always seem to find a way to get on board any type of ship no matter what.

To see more old pictures of cats with sailors, visit the U.S. Naval Institute site where you can read more here.