Mine never touched my corals but they played havoc on my coralline. I tried pulling them out by hand but it was a real pain trying to grab them. I ended up buying some of the long thin tongs (similar to the Eheim tongs). Way easier than using your hands! I was able to pull out 50 in only a few short minutes. A few sessions like that and their numbers were back in check. Every few months I'll pull out a dozen or so to keep the population sparse.