Hitch hikers into our aquariums are often given a bad rap. Tanks are frequently devastated by them, as the hitch hikers are typically some sort of undesirable pest. Acropora Eating Flatworms, red Planaria flatworms, eunicid worms, and red bugs are just a few that immediately come to mind. But not all hitch hikers are bad. We’ve heard plenty of stories whose hitch hikers were actually quite welcomed into an aquarium. Things like sand sifting cucumbers, Acropora crabs, micro brittle stars, and algae grazing snails are just a handful we can think of. On top of that, there are those hitch hikers that sort of fall in between those two categories. Things like stomatopods (mantis shrimp) are both desired and hated, so it all depends on the owner of the tank. Getting to the main point…not all hitch hikers are bad, so you may not want to try to eradicate all of the life on your live rock in an attempt to start with a sterile tank.