I rearranged the tank recently when I had to hunt down my BN plec. I was also looking for the otto that was in there once upon a time and when I rearranged all the rock along with stirring the sand a little the syn went ballistic. He now refuses to stay at the bottom of the tank and huddles himself near the intake of one of the filters at the top. Not sure why this happened as it hasnt happened on previous rearranging. Any thoughts?