I have a 4.5 year old pond about an acre in size and around 15 feet deep.  Well stocked with bass, catfish and bluegill.  I ice fished on it for the first time in year 2.  The fish were small but the bite was excellent.  I always caught all 3 species at rates of approx. 10 fish per hour.  As my fish have multiplied and grown (bass up to 4 pounds, catfish 5 plus and bluegills up to 9 inches) my ice fishing catches have declined steadily.  The fishing during the summer is excellent.  I've tried shallow, deep, weedline, etc.  At last ice a few weeks ago, I only caught 3 catfish in 2 days!  I'm generally using jigs with redworms or mealworms.  Where are the bluegill??  I had the same issue last year for the 1 day the ice was good enough.  I have noticed when I have kept/cleaned fish that they are full of snails.  That is all I find.  My only guess is that whatever they are eating in the winter they are so single minded and conditioned to eat whatever it may be that they hardly look at my bait.  It's a small pond for god's sake!  They can't leave...I'm sure I'm contacting fish but they refuse to bite.  I'm so excited to fish this weekend but I don't want to be disappointed again.  Any suggestions or explanations?  By the way, I checked the ice yesterday.  4 inches of clear, hard ice.