ABSTRACT This paper presents the results of investigations conducted between 2011 and 2013 to discover additional populations of Mormotomyia hirsuta Austen. These investigations were conducted primarily in the relatively dry savanna of eastern Kenya, focusing on small hills and rocky outcrops resembling that of Ukasi Hill, the type locality of the “terrible hairy fly”. Investigations were conducted at 144 caves and at ground level, directly below 104 above-ground, narrow, horizontally-oriented fissures, often on near-vertical rock faces. Evidence of Mormotomyia was not found in any of the caves investigated. During the dry season, however, desiccated corpses of Mormotomyia were discovered embedded in a matrix of dried bat guano adhering to the rock face directly below fissures at Ngauluka and Makilu Hills, also located in the Ukasi area. Later, rainy season visits to these two hills revealed populations of living Mormotomyia while, contemporaneously, flies were absent from the type locality. Like the type...