Flesh moths looked identical to species of moths native to Earth, but were much larger. They were attracted to sources of light and rapid movement. When a single flesh moth located prey, it could then emit a deafening blast of sound to summon the rest of its swarm. They were highly attuned to motion, and were less likely to attack prey which stood perfectly still. (TV: It Takes You Away)
The Thirteenth Doctor, Graham O'Brien and Yasmin Khan encountered flesh moths on one anti-zone which connected the Doctor's universe and the Solitract plane. These flesh moths were attracted to Ribbons' lantern. Ribbons distracted the first moth with meat, which it quickly devoured. Another flesh moth summoned the others and knocked out Ribbons' lantern. The swarm attacked Ribbons when he made a motion towards the Doctor's sonic screwdriver, stripping his flesh down to the bone.