[tang daddy]

Clicking could mean a mantis but it could also mean a pistol either way if it was a mantis you'd never fing it unless you actually saw it hiding in the rock to guess which rock would be like having a bunch of keys like 20 and 1 car.

Mantis are really smart when they hide they cut a rock and stick it snug to the entrance of their hole making you think that nothing was there.

Baby mantis can grow to a good size but would take awhile to be big.

You could try baiting the culprit with a piece of smelly prawn at night in a bottle turned on its side and a blue led shinning at the bottle sitting waiting.

Your lawn mower blenney sits on rocks so quite possible it could've gotten picked off, the mandrin was eating pods, I know you have alot of pods however a mandrin could clean shop in a month, I know my pseudo did it in 3 days. Unless the mandrin was eating brine or mysis and really fat he could have died of hunger or maybe even cyanide as 90 odd % are caught with cyanide and the rest probally speared.

If the clicks are so loud you can hear them from the other room it very well is a mantis.