Researchers have found variations in cutaneous pH of bats that may have implications on pathogenic factors and potential therapeutic targets for treating skin conditions. They used non-invasive probes to measure the pH of bat flight membranes in five species with differing susceptibility to white-nose syndrome. They found that some species were more acidic than others and that juvenile bats of all species had more acidic skin than adults during maternity season but no difference during swarming. Bat skin was more acidic in summer as compared to winter, which is a pattern also reported in humans. Skin pH was more acidic in captive vs wild bats of a species, suggesting environmental impacts – potentially roosting substrates – on skin pH, and this may be reflected in wild bats using varying roost types across seasons.