But there are already some beavers in the wild in the UK. The reason you might not be aware of this is that they don't go around eating children or causing flooding so don't make the news much. They weren't hunted to extinction because they damaged the environment but because people ate them and used their pelts as well. That, alongside manmade interference in their habitats, jeopardised their survival. Just as an aside, castoreum (anal gland secretion) was, and still is, used in perfume and also in foodstuffs. It's used by companies like Yoplait, Ben and Jerry's and Haribo in the States to replicate raspberry aand vanilla flavours.