haha, my peppermint shrimp sounds the exact opposite of your shrimp's, he's almost always out and about looking for something to eat and then every once in a while he'll go hide in the live rock. I always try to feed mine directly along with my cleaner shrimp although it's not necessary since their scavengers and will probably find some extra mysis in the rocks but they always seem so happy when the turkey baster enters the tank and I can't resist feeding them. As for your shrimp, I'd definitely still keep an eye out for him if what you found was a molt.