Bipolar bears, also known as north-south bears or nanuq-depressive bears in the Inuit language, are a bear species native to both the Arctic and Antarctic. Bipolar bears migrate between the north and south poles so that they remain in winter conditions year-round. They likewise alternate between “high” states of mania (in the north) and “low” states of depression (in the south). Why these geographically-determined mood swings should be polar in nature has baffled conservationists and animal psychiatrists alike.