Body length is about 22 cm; The back of the body is brown, generally the belly is chestnut red, and sometimes even the inside of the limbs is chestnut red; Some individuals have only a red belly line, or even no red at all. The tail is almost as long as the body, the tail hair is dark brown and the tip is light brown, and some individuals have a gray-white tail. Red-bellied squirrels are arboreal and diurnal animals, and are most active in the morning twilight. Different from general cognition, they don't live in tree holes, but weave a spherical nest with twigs with leaves hanging high from the treetops. The nest is bigger than a football and is filled with soft bark, fiber and other comfortable materials. Both male and female red-bellied squirrels have their own tree nests, sometimes more than one. Naturally, female squirrels also raise young children in their nests, with two babies each, usually one to two children a year. Red-bellied squirrels mainly feed on fruits, flowers and leaves of plants, and occasionally take some animal food. In Taiwan Province, it may be due to the felling of low-altitude broad-leaved forest trees in the past and the large-scale afforestation of Cryptomeria fortunei, and the sudden loss of habitat biodiversity, resulting in the damage of Cryptomeria fortunei afforestation land by squirrels. The bark of trees is bitten, and it can be deformed to death, causing huge losses. Therefore, the red-bellied squirrel has been named as a forest pest and attracted much attention.

There are many kinds of squirrels, about 240 in the world and 26 in China. Among them, squirrels living in the Woods are very common in northeast China and north China, so they are also called ordinary squirrels. Its body is slender and its hair is gray, dark brown or reddish brown, so it is also called gray squirrel.

When people go up the mountain, they can often see squirrels scurrying about on pine trees, with a long, fluffy tail that often reverses to the back. Sometimes, two front feet hold a pine cone and chew it with sharp front teeth, just like a incense burner worshipping Buddha in a temple.

Squirrels build nests on dense branches, or use the abandoned nests of crows and magpies, and sometimes make nests in tree holes; They eat not only wild fruits, but also twigs, buds, leaves, insects and eggs. As soon as autumn comes, squirrels begin to store food. A squirrel often stores several kilograms of food in several places, and sometimes sees squirrels drying food on trees to prevent them from spoiling and mildew. In this way, in the cold winter, squirrels will have nothing to eat.

Squirrels are usually active during the day and more active in the morning. It has good hearing and vision, and is agile and lively.

Squirrel's fur is light and warm. Although its quality is not as good as that of otter and sable, it is one of the important fur animals in China.