Madagascar Tree Boa (Sanzinia madagascariensis) - Whilst known as a ‘tree boa’, this snake is less arboreal than other tree boas, using trees only when hunting. It is a nocturnal snake, feeding on small mammals and birds, seeking them out using the heat-sensitive pits around its mouth that enable it to hunt for warm-blooded prey in complete darkness. The victims, once captured, are constricted by the powerful coils of the boa which tighten as the prey struggles, restricting the blood flow to the heart and ultimately causing circulatory failure. Boas are not venomous. Andasibe - Mantadia National Park - Eastern Madagascar.