This keen eye for quirk runs through Roach’s career — that, and a penchant for catchy, single-word titles: “Bonk,” “Gulp,” “Stiff,” “Spook” (2010’s “Packing for Mars” being a garrulous exception). Like haiku, these monosyllabic titles are dense with meaning, and “Fuzz” follows the pattern in evoking both the furry elements and their attempted enforcement. Below the clever surface of her prose runs a preoccupation with human occupations. You can see it in her attention to business cards and job titles, which she collects like a philatelist raiding a flea market: Human-Elephant Conflict Specialist, Bear Manager, Danger-Tree Faller-Blaster. Institutions, with their many bureaucratic branchings, provide an especially rich selection of ecological niches in which to uncover highly specialized forms of life. In “Grunt,” her 2016 book on “the curious science of humans at war,” Roach interviewed U.S. Army fashion advisers and stink-bomb engineers, delighting in discoveries such as a Hook and Loop Task Group devoted to the quest for a quieter Velcro. This curious and generous engagement with her subjects makes for world-expanding reading, even if it leaves other questions unaddressed — such as the value of investing quite so much effort into the design of more comfortable outfits for snipers.