I dunno, it's not a normal thing but in my tank amphipods were eating the tentacle tips on the smaller nems which made them get infections and slowly die off, I watched them do it quite a few times. I talked to a bunch of people about it who said it couldn't be the pods but the nems stopped dying once I nuked them, not sure what the deal was but pretty sure it's an issue that for some reason or another was unique to my tank.