Capture‐recapture, a method devised for estimating wildlife population sizes using technologies like bird banding, has been repurposed for use with “rare and elusive” human populations. Capture‐recapture is implemented to count “key populations,” groups that constitute a small portion of the general population but are at high risk of HIV infection, including men who have sex with men. Drawing on ethnographic work in Malawi, I excavate mundane and oblique forms of capture (of labor, value, and viral material) and recapture (producing captive experimental populations) through which key populations come into being. Moving beyond the critical register of dehumanization (counting men as if they were animals) illuminates how efforts to count, care for, and keep track of key populations are mediated by relations of capture and elusion that are simultaneously predatory and capacitating, and entanglements that exceed the confines of a peculiar population‐size estimate method. [quantification, population, capture, global health, biopolitics, data, Malawi, Africa]