Community health worker Vincent Niyindorera explains how he uses his legs as a bait to catch mosquitos to help local researchers map mosquito behavior in his village. Four evenings in a month, Niyindorera gathers his tools of trade – a torch, a test tube and a pile of cotton wool – and prepares for a long night in the appointed test site. There he sits in the name of science, waiting for bloodthirsty mosquitos to come for him.