Yeah peppermint shrimps seem like a’holes in my experience so far. I bought two, and I’ve had to move one to my QT observation tank (no copper) because it started eating my hammer coral as soon as I put it in there. The other one is definitely now a murder suspect in the case of the RFA. I love having shrimps in my tank - I’ve got more of them than fish at the moment with the peppermint, two blood red, two scarlet cleaners, a boxer and a Randal’s pistol. I am starting to get why many reefers don’t bother with shrimp though; they can be bad citizens and they can be a food source for some fish which limits your stocking list just a bit. Still, I think out of RFAs and shrimps I’d take the shrimps.