Some children leave the family bed of their own accord; others leave because their parents feel it's time. Some leave because a new sibling is on the way or has just been born. Some children make the transition as early as eighteen months of their own accord; others don't decide to leave until adolescence. Most kids who move out of the family bed on their own pick an age somewhere in between — perhaps between four and eight. Of course, children who leave at their parents' suggestion may be leaving at almost any age, depending on the reason. Is it because the child is too big, wiggles too much, takes up too much of the bed, and interferes with your sleep? Is it because of another pregnancy? Is it because either you or your spouse is simply no longer enjoying the cosleeping arrangement? Is it because of some change in the physical layout of your house, perhaps a new house with a smaller bedroom that cannot accommodate your king-size bed?

As a transition, your child may want to sleep on a separate mattress on the floor of your room. This is especially a good solution for the toddler who isn't quite ready to fully separate, though even older kids may want this arrangement for a while. If you're ending a cosleeping arrangement because of a new baby, it's best to ease the first child out of the family bed a few weeks before the new sibling is expected.

If moving the child out is your idea, ways to tempt him include suggesting that he's such a big boy that maybe he wants to sleep in a big-boy bed in his own room; offering him theme-decorated sheets or a special bed such as a canopied bed or one shaped like a race car; or offering him a gift unrelated to the actual sleeping arrangements but offered as a gift or privilege “now that you're old enough to sleep in your own bed.” The child may want his own bed for privacy reasons. He may want his own bed even though you're not particularly eager to see him go. But if he is ready, let him go. The bed may feel empty for a time. But leaving the family bed is part of growing up. Sooner or later, whether it's at your behest or on his own, it's going to happen.