Giant rat-like creatures invading Irish rivers

Giant rat-like creatures called coypu are spreading in the wilds here, having been first introduced to Ireland as pets.
Native to South America, the coypu is one of the biggest rodents in the world, weighing 5kg-7kg and measuring a metre long.
Also known as the river rat, it is often mistaken for an otter - but can be identified by its long, round tail and orange or yellow teeth.