We are moving the tanks to the new house, so I was reaching in the sump grabbing the chaeto and placing it into bags. I knew that the chaeto was full of bristleworms, but I didn't think much of it. Next thing I know both of my hands were stinging, very bad! At one point I thought I might have to go to the hospital because it hurt so bad. I put my hands under the halides and I could see all of the stingers sticking out. Well upon further inspection I saw the largest bristleworm that I've ever seen, in person. I've seen pics online of how big they can get, but this thing was huge! I would guess that it was about seven or eight inches long fully stretched out. Well here's a picture of it. Don't mess with these guys, they hurt!