Nairobi fly is the common name for two species of rove beetle in the genus Paederus, native to East Africa originating from Tanzania.

[5] Heavy rains, sometimes brought on by El Niño events, provide the conditions for the Nairobi fly to thrive.

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, often at night, when sleepers inadvertently brush the insect from their faces.

[3][5] Research from a group at the University of Hyderabad in 2024 suggest that the use of LED lights at night may be a solution to prevent acid fly attacks.