When it comes to falling asleep, I can only doze off in certain positions. If I'm taking a nap, I generally fall asleep fastest while lying on my stomach but can occasionally fall asleep on my back. If I'm hitting the sack for the night, I can never fall asleep on my stomach, and must be on my back. However, if I wake up in the middle of the night, I can go back to sleep on my stomach with no problems. Booty has the same behaviour -- she can only fall asleep in her bed, or on any reasonably flat surface.