The name Nairobi fly or Kenya Fly is applied to two species of beetle which live in East Africa, Paederus crebinpunctatus and Paederus sabaeus . They are species of the rove beetle genus Paederus, and are black and red in colour, and about 6–10 mm long . They live in rotting leaves where they lay their eggs.
The beetles neither sting nor bite, but their haemolymph contains pederin, a potent toxin that causes blistering and Paederus dermatitis. The toxin is released when the beetle is crushed against the skin. People are advised to brush or blow the insect off their skin to prevent irritation .
Heavy rains, sometimes brought on by El Niño events, provide the conditions for the Nairobi fly to thrive.Outbreaks have occurred in 1998