Roll-up behaviour and habitat

Sowbug vs pillbug

Sowbugs and pillbugs are crustaceans, not insects. Pillbugs (roly-polies) roll into a ball. Sowbugs usually cannot. They share habitat and control: wet organic matter against a foundation. Steps for getting them out of a house are on the Sowbug and pillbug page.

Roll-up behaviour and habitat

PillbugSowbug
Roll into a ball?YesGenerally no; trailing appendages
Folk namesRoly-poly, pill bugWoodlouse, sow bug
HabitatUnder pots, mulch, damp boardsSame moisture postcard
Eat the house?Wet dead plants, not sound timberSame

Shared moisture control

Pull mulch, fix downspouts, dry the basement, seal doors. Arizona irrigation against stucco still makes a forest floor. Rain invaders that are not isopods: Millipede and Earwig.

Species pages

Each species article has the control sequence and safety notes. This page only splits look-alikes.

Common questions

Do I need different poison for sowbugs vs pillbugs?

You need a drier foundation. Habitat first for both.

Sources

Written by the Pest Kill Editorial Team. Published August 25, 2026. Last reviewed September 13, 2026.