Pillbugs are cave-dwelling creatures typically found in small, narrow caverns. They do not pose much of a threat, but Pillbugs will cause damage by ramming if their path is obstructed.
Pillbugs sense the environment around them with a series of sensitive antennae that extend to the tips of their tails, and use these to navigate. Their diet consists mostly of moss and fungus, and while they forage for food they crawl along their vulnerable bellies. When they sense a threat or an obstruction, they curl up into balls and ram anything in their way.
Though their outer shell protects them from most attacks, Samus can use the concussive impact of her Bombs to jar them loose, stunning them temporarily and exposing their vulnerable undersides, and then drop more bombs to destroy them.
- "Pillbugs prefer to dwell in dark caverns, though they can exist in lit areas. Navigating with a series of sensitive antennae, they roam through caves in search of moss and fungus. Pillbugs can move rapidly, and will ram unwary targets to clear their path as they search for food. A Pillbug can be jarred loose from a surface with a concussive blast: doing so reveals its vulnerable belly." — Logbook "Pillbug" (Metroid Prime 2: Echoes)