The Puff adder is a venomous viper species found in Sub-Saharan Africa and on the Arabian peninsula. This snake is responsible for causing the most snakebite fatalities in Africa owing to various factors, such as its wide distribution, frequent occurrence in highly populated regions, and aggressive disposition. The color pattern of Puff adders varies geographically. Their head has two well-marked dark bands: one on the crown and the other between the eyes. On the sides of the head, there are two oblique dark bands or bars that run from the eye to the supralabials. Below, the head is yellowish-white with scattered dark blotches. Dorsally, the ground-color varies from straw yellow, to light brown, to orange or reddish-brown. This is overlaid with a pattern of 18-22 backwardly-directed, dark brown to black bands that extend down the back and tail. Usually, these bands are roughly chevron-shaped but maybe more U-shaped in some areas. They also form 2-6 light and dark cross-bands on the tail. Some populations are heavily flecked with brown and black, often obscuring other coloration, giving the animal a dusty-brown or blackish appearance. The belly is yellow or white, with a few scattered dark spots. Newborn young have golden head markings with pinkish to reddish ventral plates toward the lateral edges.
Puff adders are found in most of sub-Saharan Africa south to the Cape of Good Hope, including southern Morocco, Mauritania, Senegal, Mali, southern Algeria, Guinea, Sierra Leone, Côte d'Ivoire, Ghana, Togo, Benin, Niger, Nigeria, Chad, Sudan, Cameroon, Central African Republic, northern, eastern and southern Democratic Republic of the Congo, Uganda, Kenya, Somalia, Rwanda, Burundi, Tanzania, Angola, Zambia, Malawi, Mozambique, Zimbabwe, Botswana, Namibia and South Africa. These snakes also occur on the Arabian peninsula, where they are found in southwestern Saudi Arabia and Yemen. They have also been reported to be found in the Dhofar region of southern Oman. Puff adders live in all habitats except true deserts, rain forests, and (tropical) alpine habitats. They are most often associated with savannahs and rocky grasslands.
Puff adders are solitary and nocturnal creatures. Although they spend most of their time on the ground, these snakes are good swimmers and can also climb with ease; often they are found basking in low bushes. One specimen even was found 4.6 m above the ground in a densely branched tree. Puff adders are normally sluggish and rely on camouflage for protection. When agitated, they can resort to a typical serpentine movement and move with surprising speed. If disturbed, these snakes will hiss loudly and continuously, adopting a tightly coiled defensive posture with the forepart of their body held in a taut "S" shape. At the same time, they may attempt to back away from the threat towards cover. Puff adders may strike suddenly and fast, to the side as easily as forwards, before returning quickly to the defensive position, ready to strike again. They can strike to a distance of about one-third of their body length, but juveniles will launch their entire bodies forwards in the process. These snakes rarely grip their victims, instead releasing quickly to return to the striking position.
Puff adders are polygynandrous (promiscuous) meaning that both males and females have multiple partners. Their mating season usually takes place between October and December. During this time females produce a pheromone to attract males, which engage in neck-wrestling combat dances. Puff adders are viviparous and females give birth to 50-60 live young after the gestation period that lasts 136-159 days. Newborns are 12.5-17.5 cm in length; they are completely independent at birth and are ready to care for themselves. Young Puff adders usually become reproductively mature when they are 4 years old.
There are no major threats to Puff adders at present.
Puff adders play are important predators in their ecosystem as they control populations of many prey species they feed on. They also help control populations of pests as these snakes are often found near human settlements and prey on rodents. Young Puff adders prey on various insects and also can play a useful role for farmers.