We had that issue with my older child except it was his swing, and he was never a good napper. WIth my daughter, it took a little bit of trial and error to start getting her to sleep consistently in her crib at nap time. I tried to make the envionrment similar to what it as night time. I put up blankets over her window, play music softly, etc. You also want to make sure you are putting him down before he is overtired. Start watching for sleepy cues, such as yawning, rubbing his eyes, or slowing down on his movement/acitivy. As soon as he starts looking tired, put him in his crib and tell him it's time to go to sleep. I give my daughter a lovey that she only gets at nap and bedtime and her blanket. It took a few days of me going in & out of her room, gtiving her the paci, rubbing her back before she started sleeping well in her crib during the day. Just keep working at it, soothing him in his crib.
at 3:15 PM on Sep. 21, 2010