My formula fed 10 week old is getting his daily quota with feeds however sometimes during the afternoon he will go up to 6 hours without asking for it and goes crazy if I try to feed him when he isn't hungry. He also sleeps through about 7 hours before waking for a feed. He is otherwise happy and growing, weight seems to be OK - it's just a lot less than some others seem to feed and just looking for reassurance that I'm not depriving him?! Is he maybe just "packing in" with big feeds so he can snooze and relax for a few hours?