My watchman leaves his shrimp buddy every once in a while, usually after I’ve done some major rock moves or other changes in the tank. He suddenly starts swimming all over the tank, at all levels (kinda looks like he’s surfing). He has been known to do this for a couple days at a time.
Not sure exactly “why” he does it. My GUESS is that since he IS the “watchman” in the pair, he’s scoping out the tank, getting a look at all the rock work, looking for the best, most defensible spot for he and his buddy to move into (OR Ernie and Burt are having domestic issues because Burt was looking at that hot new peppermint shrimp)