Wild mammals include foxes, hedgehogs, stoats, weasels, mink, grey squirrels and badgers. Today, mammals include shrews, voles, badgers, otters, stoats, weasels, hedgehogs and fifteen species of bat. The main predators of shrews are owls, weasels, stoats, and red foxes. The genus "Mustela" includes the least weasels, polecats, stoats, ferrets and mink. Possums, rats, and stoats can all be killed with traps. Stoats may prey on young hares. Also present are badgers, foxes and stoats. Pests include stoats and possums, which arrived in the 1990s. Cases are known of stoats preying on young muskrats. Farmers began demanding the introduction of mustelids (including stoats) to control the rabbit plague. Other terrestrial predators include rats, kingfishers, shags, scaup, stoats, and kiwi. Introduced mammalian predators, namely stoats, dogs, ferrets, and cats, are the principal threats to kiwi. At this time he also used Sealyham Terriers for hunting otters, stoats and squirrels. They use their powerful legs and claws for defence against predators like stoats or ferrets. They brought more dogs and other mammalian predators, including domestic cats, black rats and stoats.