Polar bears live on the planets coldest environments which means they need a lot of fur to stay warm. They have a thick layer of white insulated fur that covers a warming layer of fat and fur grows at the bottom of their paws to give them a good grip on the ice and protect them from the cold. Polar bears are excellent swimmers, they use their large slightly webbed front paws to which allows them to swim at speeds of up to 6mph. They can swim for days at a time and have been seen swimming hundreds of miles away from land. They are the masters of the Arctic at the top of the food chain, with a strong sense of smell they can smell their prey up to 10km away which they use to find seal breathing holes. They are opportunists and spend most of their days hunting but only 2% of their hunts are successful which means they scavenge carcasses and eat them when unsuccessful. Polar bears are generally solitary animals other than when they mate where they will remain together for a week or more. A females gives birth in the winter, usually to twins. The female aggressively protect their young cubs with no help from their solitary male mates who instead will try to kill the young of their species. Mothers are very attentive, touching and grooming their cubs who will stay with them for 28 months to learn the skills they need to survive in their natural habitat. As polar bears live in the Arctic areas they are at a huge risk from the threats that they face especially climate change.