Most people react to snakes with fear. Yet, very few snakes are lethal or even poisonous. India, in fact, has only five known varieties of deadly snakes: cobra, krait, Russell's viper and saw-scaled viper, and the recently discovered hump-nosed pit viper. A small brown snake with markings in lighter/darker brown, the pit viper or chirutta inhabits deciduous and secondary forests across the western ghats, in Kerala, Tamil Nadu, Karnataka, Goa, Maharashtra and Andhra Pradesh.

Previously, it was believed to be harmless, but now Joseph K Joseph, Little Flower Hospital, Angamaly, Kerala and Ian D Simpson, a herpetologist in the World Health Organization's snakebite treatment group, has found its bite to be fatal. The pit viper's bite takes effect after twelve hours, what Simpson calls its