One of the biggest museums in the world, the Hermitage Museum in St. Petersburg, Russia, uses over 65 cats to protect over 3 million pieces of artwork from rats and mice. Three people work full-time to take care of the cats including Irina Popovets who is quoted in a CBC News video as saying, “They’re not just mascots, they’re really employees of the Hermitage and they play a very important role.” The television show Museum Secrets ran a segment on the cats and said that cats have been an important part of the museum since the 18th century.

via CBC News and Nag on the Lake