"welding head" is the old name of Agkistrodon acutus, that is, the general name of all species under Agkistrodon acutus. Generally speaking, the "welding head" we refer to is one of the genera-Agkistrodon acutus, which is widely distributed in Zhejiang, Anhui, Fujian, Taiwan Province, Jiangxi, Henan, Hubei, Hunan, Guangdong, Hong Kong, Hainan and other places. Therefore, it is incorrect to say that "welding head is a rare species endemic to Hunan". I guess the landlord refers to the snake "Mangshan welding head", which is also found in Guangdong, so Mangshan welding head is not unique to Hunan (Mangshan welding head has been artificially propagated abroad).