Mine has its moments, like said before usually when going near its turf. When I first got it, and introduced a peppermint shrimp, he chased that thing for days then all was good. I don't have any issues at all now (a year down the road) Current tankmakes are a clown, zebra bar goby, six-line wrasse. oh and a neon goby I almost never see, emerald crab, cleaner shrimp, lots of CUC. I do notice with having more tankmakes he does hid out in the caves more than when it was just two other fish with it.