Few species of reptiles or amphibians are found in Great Britain or Ireland. Only three snakes are native to Great Britain: the common European adder, the grass snake and the smooth snake; none are native to Ireland. In general, Great Britain has slightly more variation and native wild life, with weasels, polecats, wildcats, most shrews, moles, water voles, roe deer and common toads also being absent from Ireland. This pattern is also true for birds and insects. Notable exceptions include the Kerry slug and certain species of wood lice native to Ireland but not Great Britain.