Agkistrodon 1 species. Also known as red chain. Non-poisonous snakes distributed in all provinces of China (except Ningxia and Qinghai-Tibet Plateau). The total length is about 1 m. The back is dark brown. It is named after more than 60 narrow red stripes. The dorsal scale is smooth, or there are several rows of ridges in the center of the posterior segment of the body. Buccal scales often enter the orbit. The back of the head is black and the scales are red. There is a ∧-shaped erythema on the occipital part, and a black stripe behind the eye socket reaches the scales of the seventh upper lip backwards. Red chain snakes inhabit plains, mountains, hillsides, roadsides, bamboo forests, cottages and waters, and sometimes enter houses. Often curled up in a ball, squatting under the haystack. There are more activities at night. Feed on fish, frogs, * * * *, lizards, snakes, birds, etc. Oviposition, laying eggs in August 10 or more, egg diameter 15× 13mm. The newly hatched snake is 232 ~ 242 mm long and has egg teeth on its snout.