I got a 2" fuzzy dwarf the other day. The guy at the lfs told me had had fed him the smallest feeder fish he had. I put him in my tank, and he fed real good, on my peppermints.
It would seem to me that if you have had it for a month, and havent seen it feed, then it is eating something. Is it in any distress or look like it is declining in health??
My dwarf is mainly active at night, but when I feed the tank, he is moving around the rockwork, and I am sure he is feeding too.