Cats have a knack for slipping into places they don’t belong, but aboard ships, they served an important purpose. Not only did they keep rats and mice under control, but they also boosted the morale of sailors. The cat pictured here, lounging in the sun on the deck of the Durham Castle liner in 1928, seems to be simply enjoying the peaceful vibes.

Of course, one of the most famous ship cats was Jenny, a mouser on the Titanic. Before the ship set sail for New York, Jenny gave birth to a litter of kittens. Accounts of what happened to her vary widely. But, according to Jim Mulholland, a stoker, when the Titanic was docked in Southampton, he saw Jenny carrying her kittens off the ship. Taking it as a bad omen, he decided to leave as well, a decision that saved his life.

A global history of cats in vintage photos