Bristle Worm Gets Eaten for Lunch

It is totally normal to have a few Bristle Worms in your tank.  They will not your harm tank when they are low in numbers. But if you notice them climbing out of your rock in droves, everytime you feed ... then you have a Bristle Worm problem.

An over population of Bristle worms can be a problem in a reef aquarium, because they may start picking at your corals as they look for more food sources.

There is not many Bristle Worm Predators that you can add to your aquarium that are reef safe.  Not many other critters want to eat bristle worms.  Except for ... the Arrow crab. 

Arrow Crabs love to eat bristle worms and it is even funny to watch.  They have pinchers for hands and they hold on with one hand and eat with the other.

Arrow Crabs are generally reef safe because they are too slow to catch other fish or inverts.  They also don't have big and powerful claws like other crabs do.  They have little weak claws, suitable to catching and eating slow moving worms.