My DS is 21 months old and I have just started thinking about moving him out of his crib. We just set up a bed in our guest room, so now he keeps talking about the 'big bed' (which is also what he calls our bed). Last night he wanted to lay down in the "big bed' which he's never wanted to do before. We have a crib that will convert to a toddler bed by taking the sides off. My concern is that he is a serious mover and shaker in bed. He will cover the entire length of the crib and back several times while he's sleeping, so I worry about him falling out. When did everyone else move their LOs from the crib ?