Every 3 hours, generally. My oldest who is 3 JUST started making it through the night a few months ago. He nursed every 2-3 hours during the night until he was 16 months old and then had night terrors that have just finally seemed to go away. I'm pretty much in for the long haul here and expecting my youngest won't sleep through the night for a while. But he at least sleeps in his own bed (in my room), whereas my toddler has always slept in my bed. Their dad works night shift, so neither will sleep in their own rooms for quite a while.