The accumulation of decomposing animal and plant material and waste product is often referred to as 'detritus' or 'mulm'. In the description of natural habitats, the term may be used to describe the bottom of an area such as 'forest detritus' or 'leaf detritus' (leaf litter) In fishkeeping, a build-up of detritus suggests an increasing amount of waste material at the bottom of the aquarium which may need removing by siphoning or gravel-cleaning. Too much detritus can increase the chances of bacterial infection, or alternately, may provide nutrients for plants.