my pair has never bothered an invert ever. My male consumed all my chromis in short order though. I recently added about 2 dozen peppermint and 5 cleaner shrimp to my tank (under the cover of darkness). They are really secretive fish, so when I put my hands in the tank a couple times, they went for cover. It made the additional quite easy. And they still have looked at the shrimp as food. The cleaners actually swarm the male when he locks himslef into a crevice at night.