Just thought it might be a good idea to post some links, and some general descriptions for the commonly found hitch hikers that come in with live rock. Eeeek! There are BUGS in my tank! Most likely not. There are a variety of micro fauna living in every healthy system, especially reefs. Copopods and amphipods are some of the most common ones around. What is that pink thing? Worms, worms, wonderful worms! Worms are the detrivores of the aquarium. There are many kinds--some bristle, some not, but most are harmless. Peanut Worms and bristle worms are very common, and are beneficial additions to the tank. Who is making all these little white coils? Stony tube worms! Some worms live in holes in the rock, others build their own, sometimes using secreations to glue together what ever is handy--crushed coral, sand, etc. They are not harmful, and tend to fluctuate--sometimes they are all over, other times you'll have to search to find more than one or two. Something clicking this way comes... Could be a problem child, otherwise known as a mantis shrimp. These little buggers can be the bane of the tank, or the centerpeice of a system. Two basic varieties--clubbers and spearers. Lighting fast, they are also knick named thumb splitters for good reason. The making a clicking noise when hunting, usually at night, and will kill mobile inverts (crabs and shrimps) and small fish. Eels and octopus will make short work of them, but may not work out in a reef. Several methods for their removal are available--commercial traps, DIY traps, or patience and some freshwater. More to come--including links to some of my favorite hitch hiker identification web sites! Please feel free to add your own critters and links as well!