Mischievous YWG or is something wrong?

[tlhood]

I have had a yellow watchman goby for almost a month now and I've noticed some behavior that I am unsure about. During the day he is still pretty shy and doesn't venture far out of his and his girlfriends cave (firefish). He has burrowed a couple holes, but I noticed he filled one up today and has resumed bunking with the firefish. He eats every day, I generally feed him twice a day, alternating between flakes, mysis, and brine.

The behavior that worries me is that when the lights go off for the night (the tank is in my room so the moon lights go off too) I can hear him jumping. I have found him in my overflow box several times. I have remove it for the past two nights because I worry he might get hurt pressed up against the grate. My tank is an rsm 130 so it has a full lid, however there is a one inch gap between the lid and the rear filtration compartment. It worries me that he will jump into the back. He also seems to like to rest up against the grill? Of the overflow. He also seems to swim around the top of the tank at night, tends to rest on my return pumps, and swims around my clowns when they go to their corner for the night (also at the top of the tank). There is plenty of live rock with hiding holes and open sand. I don't see him sifting that often.

All my corals look healthy, my firefish and clowns look and behave normal. Ammonia nitrate nitrite all 0, phosphates are a bit high as I feed them a lot, around 0.2. Temp is 78 and salinity is 1.024.

Is my goby just a bit of a brat, or is this totally abnormal behavior?(the swimming at the top at night and resting against the overflow).

[FishyFishy!]

I think that it would suggest that he is being chased up there by something/someone. You should try adding a pistol shimp in there to see if that might help. They can gang up and create a nice burrow.

I had a few YWG's without pistols, and they all perrished in the same way. It is strange behavior, but maybe thats just how they are when not accompanied by other YWG's or pistols. Can anyone else chime in here?

I would also use some egg crate and seal up that gap into the filter compartment.

[tlhood]

Hm. it would be hard to imagine something in my tank chasing him... Unless he has a phobia of hermit crabs at night.

I have some egg crate but I can see him going straight through one of the holes. I was planning on going to home depot and getting some rigid plastic that I can glue to the underside of the lid to act as a partition. I would hate to come home after the long weekend and find him in the back. It's so cramped back there I would never be able to get him out.