A few weeks ago Timmy figured out how to climb out of his crib.  Even though all the baby websites say don't rush to get a toddler bed right away, try lowering the matress to make the crib safer, we got a toddler bed. Having watched him climb out of his crib it made me  very nervous, because if he did fall he would land on his head for sure. The mattress was already as low as it could go so the only way to make it safer was to get rid of it. The transition hasn't been too bad. He can't reach the doorknob in his room to open the door, so he fortunately can't wander around if he wakes up. He definitely know the bed is for sleeping in. I've only found him asleep on the floor a couple of times and that was during nap time, not a night.