In the middle of the 20th century, a group of Soviet scientists set about introducing new species of mammals to the Caucasus. They imported a wide variety of species, from South American chinchillas to Chinese raccoon dogs. However, when they introduced the swamp rat, also known as the coypu or nutria, to Azerbaijan, they couldn't have known they were unleashing a rodent that would become one of the world's greatest pests.
Curious? Check out this gallery to learn more.