These worms build their very hard white tubes on rocks and piers. They make large colonies in the intertidal zone. Often the colonies make thick rings around the rocks and pylons. The armoured tubes protect the worms that live inside. Thousands of other small creatures find protection among the gaps between the tubes. The opening of the tubes is protected by a flap.
The worms are about 3 cm long. When the worms are covered by the sea, they open their flaps and extend their feathery green and white tentacles. These tentacles are able to collect microscopic food particles from the sea. The tube worms never move out from their protective tube.