An old Russian experiment showed how foxes were domesticated into people’s doglike companions. Only the top 5 percent of tame foxes are allowed to breed. The rest, who are perfectly friendly, are either sold to fur farms or distributed as pets. Each fox costs about $7,000. Even though they are domesticated, they are predators by nature. They need a lot of space and cannot be kept in a cage for long. They love to play anything and crave attention.