Unknown Visitor????

[sparkie]

Hi Everyone,
This is my first post, so I apologize if I am posting in the wrong area.
I have a 55 gal FOWLR tank just under a year old. I have a 3" crushed coral bed, 45lbs of live rock and 10lbs of lava rock.
My existing known residents are 6 damsels, 2 percula clowns and a strawberry pseudochromis, appox 24 blue leg hermits, 6 turbo snails and a cleaner shrimp.
Last week I added two additional small live rocks, approx 6lbs. This evening when I came home from work I noticed an area of the tank was dug out all the way to the bottom and the crushed coral was piled up behind the back of one of the rocks.
All the fish are fine, no one is missing and the hole was not there yesterday. :notsure:
Has this ever happen to anyone out there or does anyone no who might be digging in my tank?
Eddie

 

[teen]

its possible a fish dug the hole. you may have a hitchhiker pistol shrimp. maybe a powerhead or something fell down and the current pushed the sand away, and made a hole. maybe some type of snail/conch.
thats all i got.

 

[rustyj]

Worst case is you have a mantis shrimp especially if you start to see fish come up missing. If you can take a look in the hole or go the the tank when the lights are out and see if you can see what it is.