M.K.
My son (14 months) is a moaner, as well. He recently went through a phase of waking early in the morning (5am) and moaning or intermittently crying out. We left him in his crib until 6:30am. I don't know that he was fully awake -- I think his molars were coming in and bothering him. In any case, we didn't want him to become accustomed to waking really early, so we endured an hour or so of moaning.