There are four species of Water louse in Britain that are a common among still and slow flowing aquatic habitats. They will successfully inhabit polluted waters but not those that are highly acidic. They can also tolerate low levels of oxygen and can therefore be found inhabiting stagnant water. Water louse are fairly weak swimmers that tend to walk along substrate and therefore prefer water bodies with plenty of rocks and stones to walk among and hide beneath. Their whole life cycle occurs in water with females carrying eggs in brood pouches on the underneath of her body. They typically reach full maturity within a year, feeding on detritus. Water louse are common and widespread across the UK and particularly common in Leicestershire and Rutland.