Woodlice are quite harmless and are capable of living both indoors and outdoors. The indoor woodlice are clustered in wall crevices and under skirting boards - or wherever there is dampness in the building structure.
Woodlice are killed by most insecticides which are used for household and garden purposes. Sprinkling an insecticide powder at the footings all rounds the outside of the building or house can help prevent or reduce re-infestation – this seems to deter woodlice from entering in the first place