Referred to as Bamboo pit vipers. 6 species are currently recognized. Formerly classified as Trimeresurus A distinguishing feature of Vipers is the triangular shape of the head which is distinct from the neck. Almost all members of this viperidae family are classed as ambush predators. Viperidae rely heavily on cryptic colouration to act as camouflage whilst waiting for unsuspecting prey to come within striking distance. For that reason the Viperidae family contains the worlds most dangerous snakes. It gets the name pitviper due to the “pit” located in the front of the head which is a heat-sensor for detecting it’s prey. Nocturnal and during the day inactive.

Source