Squirrel, a family of mammals and rodents, includes the subfamily Squirrel and the subfamily Ground Squirrel in Africa, and is characterized by a hairy tail. According to different living environments, the Squirrel Family is divided into tree squirrels, ground squirrels and stone squirrels.

Animals closely related to other animals are also collectively called Dendrolimus. There are nearly 35 genera and 2 12 species in the world, and there are 24 species of1kloc-0/genus in China, of which 2 species are endemic to China.

Squirrels are native to northeast, northwest, southeast and Europe, and are distributed all over the world except Oceania. Squirrels are widely distributed and can be seen throughout the cold temperate forest region. In China, it is mainly distributed in the mountainous areas of three northeastern provinces, northeastern Inner Mongolia, Hebei and northwestern Shanxi, Sichuan, Ningxia, Gansu, Xinjiang, Hunan and Guizhou provinces; Foreign countries spread westward from Russia's Far East, Japan, North Korea and Mongolia to Western Europe.

In coniferous forests, squirrels are not abundant every year, and their number depends on the number of conifer seeds in winter, because their food is mainly [1] and fruits, and sometimes seeds account for more than 97%. Squirrel's tail is very big, which can increase the resistance when falling, and the big tail can also play a buffering role like a parachute.