Wagler’s Pit Viper (Tropidolaemus wagleri) spends quite a lot of time perched motionless on low branches of small trees and bushes. It doesn’t have to move very much to change from a resting position to launching into a strike. As well as being a stealth predator it also hunts actively for warm-blooded animals such as birds, mice and rats, as well as frogs. It uses the heat sensing organs in the pits (as in the name) behind its nostrils to hunt at night, locating body heat from prey. Maximum size is about 100cm but the average adult is around 60cm, and the female is larger. It occurs in Thailand, Malaysia, Indonesia and the Philippines and assumes many different colours and forms. These two snakes were photographed just behind the bungalows at Bako National Park in Sarawak. My reading suggests that the lighter spotted snake is a male, probably a juvenile and the darker more robust beast is a female. They are venomous but most bites, it is said, are relatively minor in effect. Nevertheless for me, it is reason enough to admire the jungle from well maintained paths or boardwalks.