Tigers usually rest on the ground. As tigers living in temperate zones, the ability to keep their abdomen warm in winter is a critical factor, so the Northeast tiger has the longest abdominal hair among all tiger subspecies.

Sloth monkeys, the world's only poisonous primates

During the long evolutionary journey, the brain capacity and the complexity of the nervous system of primates have been increasing, and correspondingly, their intelligence has become higher and higher as a result