Black mamba (Dendroaspis polylepis) using its tongue to smell. Snakes use their tongues for collecting chemicals from the air or ground. The tongue does not have receptors to taste or smell. Instead, these receptors are in the vomeronasal, or Jacobson's Organ, which is in the roof of the mouth. This venomous snake is native to parts of sub-Saharan Africa. Its skin colour varies from grey to dark brown but juvenile black mambas tend to be paler than adults and darken with age. The snake is called a black mamba due to the colour of the insides of its mouth which is described as "inky black". The venom of this deadly snake is both neurotoxic and cardiotoxic. Black mambas are both arboreal and terrestrial. Photographed in controlled conditions at the Hoedspruit reptile centre, Limpopo province, South Africa.