Ragworms are predator worms with strong jaws; a large ragworm can produce quite a bite! They have lots of small legs, which explains why they are also called marine centipedes in Dutch. They emerge out of the bottom to mate in the spring. Deep-sea fishermen like to use ragworms for bait because fish like to bite into them. However, these worms are more difficult to dig up out of the mudflats, making them more expensive than lugworms. That is why ragworms are cultivated. There are various kinds of ragworms. The king rag can grow as long as 40 centimeters. The estuary ragworm grows to 20 centimeters.