So 2 weeks ago i got a purple tang and lemonpeel angel fish and 95% of the time they are hiding in the rocks some times they do come out but its for about 10 seconds and then they hide again i feed nori x2 a day though the day it does not get touched but the 1 i put out at night is all gone in the morning i also have a midas blenny that is always out and swimming about feed him x2 a day with mysis shrimp with selcon and the tang and angel do join in and eat some mysis too but go straight back in the rockwork why are they hiding all the time?