kind of a funny story..my buddy james had a salt water tank that had a bunch of clown fish and some invertebrates...well he went and bought a nice huge piece of live rock. Well after about a week we started to notice fish coming up missing, like every 2 or 3 days another fish would vanish. so one night we were up playing cards and we hear this clicking sound coming from the tank. we flipped on the aquarium to find a pistol shrimp blasting another fish..It must have been in this hole in the rock...talk about nutty