The species is known to feed on a variety of small flying insects. H. horstockii’s predators include the Whiskered Tern Chlidonias hybridus (Steyn 1966; Craig 1974), Water Mongoose Atilax paludinosus, and the Cape River Frog Afrana fuscigula (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).