Black mambas inhabit a wide part of sub-Saharan Africa, from Eritrea in the north to South Africa and Namibia in the south and west. In South Africa they live along the coastal regions from KwaZulu-Natal to Port St Johns. They inhabit grassy savannas and rocky hills, in places with cover such as rocks and fallen trees, and a black mamba keeps a home range but is not highly territorial. The size of the range varies with the habitat and with how much prey there is.

The average adult black mamba is approximately 2 to 2.5 metres long, which is approximately 6.6 to 8.2 feet. National Geographic lists its weight as up to 3.5 pounds, as of November 2026, but the source does not say which animals were weighed. It has a coffin-shaped head and smooth scales, in 23 to 25 rows around the middle of the body. Its belly is lighter than its back, from cream to pale grey-green.

A black mamba is not black. Its body is gray or brown, and the inside of its mouth is blue-black, and that is where its name comes from. The species name, polylepis, comes from Greek words that mean many scales. The genus name, Dendroaspis, comes from dendro-, which means tree.

Günther named the black mamba Dendraspis polylepis in 1864, and its type specimen is the skin of an 1829 mm specimen. The mambas today are the genus Dendroaspis: four species, the black mamba and three green mambas. The black mamba belongs to the snake family Elapidae, which includes many other venomous snakes, and the bright green colour of the three green mambas is unique among snakes of this family. This once suggested that the green mambas form a single group apart from the black mamba. A 2025 study found that the black mamba's closest relative is the eastern green mamba.

How fast is a black mamba? Guinness World Records lists the black mamba as the fastest land snake, at 16 to 19 kilometres an hour (10 to 12 miles an hour) in short bursts over level ground, as of November 2026.

A black mamba moves by lateral undulation, which means it moves in an S shape. Scientists describe the black mamba as ground-living compared with the tree-living green mambas, yet it can climb well, and a black mamba can lift its head and approximately a third of its body off the ground.

A black mamba relies mainly on its eyesight to detect movement. One South African reference calls it shy but highly alert, with keen eyesight, and it has no external ears, but it is good at detecting vibrations in the ground. It flicks out its tongue to collect particles from the air, and then places them in an organ in its mouth called the vomeronasal organ.

A black mamba is active from a few hours after sunrise until approximately an hour before dusk, and it returns to its refuge by late afternoon, and it spends much of its time basking in the sun, often early in the morning. It seeks out holes underground, among rocks or under old tree stumps, and these holes are often shared with members of the same or other species, and it rests in hollow trees and empty termite mounds. It also has a permanent lair that it comes back to.

Black mambas consume small animals such as rats and birds, and they also eat dassies, which are also called hyraxes. By eating small rodents, black mambas help keep the number of rodents down.

The black mamba is the longest venomous snake in Africa, and its venom is neurotoxic, which means it acts on the nervous system. A 2015 study described two main kinds of toxin in it: alpha-neurotoxins and dendrotoxins. Alpha-neurotoxins block signals at the junction between nerves and muscles. Dendrotoxins, the next most active group in tests, inhibit voltage-dependent potassium channels.

In 2015 researchers described the venom proteome, the full set of proteins, of black mambas from Eastern Africa for the first time. In a 2018 study of all the mambas, black mamba venom was dominated by dendrotoxins I and K, while the green mambas' venoms were mostly a different group, called three-finger toxins, and the study said the black mamba's mostly ground-living life, compared with the tree life of the other mambas, makes it plausible that its different venom comes from a different diet.

The team that found mambalgins began by searching animal venoms for chemicals that could block acid-sensing ion channels, called ASICs. In 2012 French researchers reported painkilling proteins from black mamba venom and named them mambalgins. Blocking two kinds of acid-sensing channel explained the mambalgins' effect in mice: ASIC1a/ASIC2a channels in central neurons and ASIC1b channels in pain-sensing neurons.

As of November 2026, black mambas are widespread and are not endangered, and the IUCN Red List rates the black mamba as Least Concern. National Geographic lists its population trend as Stable, as of November 2026, and one account says black mambas are not endangered but face a future threat from human expansion.

Black mambas mate in the warm months, in spring or summer, and they breed once a year, and a mother black mamba lays eggs, and the eggs take approximately 2 to 3 months to hatch. A hatching black mamba breaks through its egg with an egg tooth. Young black mambas get no help from their parents, and after hatching they look after themselves. The longest recorded life of a captive black mamba was 11 years, as of November 2026. Wild snakes could live longer.

Words to know

• undulation: wavy movement
• vomeronasal: smell organ
• Elapidae: snake family
• neurotoxic: harming nerves
• proteome: all proteins
• mambalgins: painkilling proteins