Sipunculus nudus is a species of unsegmented marine worm, also known as peanut worms. The body of the adult worm is around 15 centimetres (5.9 in) in length but can reach up to 25 cm (9.8 in) in some cases. The worm is commonly found on subtidal zones of sandy shores to seabeds 900 metres (3,000 ft) in depth in temperate or tropical waters. The worm hides in sand burrows which it makes by itself during the day and may extend its tentacles out of the burrow to feed at night. Its diet consists of plant or animal tissue fragments and any surrounding sand it may ingest with it.