When Andrea Nicholls of Shropshire, England woke in the middle of the night to find her 2-year-old daughter climbing back into her crib, she decided that it was time for the toddler to switch to a bed.

Michelle Pearson's one-year-old son, on the other hand, hadn't started climbing out of the crib, but Pearson felt that he had outgrown it. "He was just such a big kid, every time he rolled over, he banged up against the bars of the crib," the Leaf River, Ill., mom recalls. "It would wake him, and us, up in the middle of the night."

And Lisa Sanders of Rixeyville, Va. bought a bed for her 18-month-old daughter when the family was expecting a second baby.

Three different children. Three different ages. Three different reasons for making the transition from crib to bed. And each one is perfectly normal.

Timing is Everything
While most children move from a crib to a bed during their toddler years, keep in mind that each child is different, and there is no definite "right" time to make the transition. "There's no one-size-fits-all age recommendation to tell parents when a child is ready to make the move from a crib to a bed," says Ann Douglas, author of The Mother of All Pregnancy Books and The Mother of All Baby Books. "You have to pay attention to your child's developmental clues and decide when he or she is ready to make the transition."

In addition, Douglas recommends waiting until your child wants a bed. "You should also look for signs that your child is interested in making the move from a crib to a bed," she says. "Not every toddler is ready to make the move at the same time."

Jodi A. Mindell, Ph.D., author of Slee ping Through the Night: How Infants, Toddlers, and Their Parents Can Get a Good Night's Sleep, believes parents should wait as long as possible before making the switch, preferably until the child is closer to 3 years old. According to Mindell, there are safety issues and security issues to consider. "Little kids have trouble understanding that they have to stay in bed, so you could have an 18-month-old wandering through the house while the parents are asleep," she says. "Plus, many children see the crib as their haven, and when they are moved from it, sleep problems can start or worsen."

Whenever you decide to make the switch, it is important that you consider your timing carefully, advises Douglas. "You don't want to make the move from crib to bed at the same time that your child is starting a new daycare arrangement, getting used to a new brother or sister, or learning to use the potty," she says. "One major change at a time is enough for a young child to cope with."

Following this "one transition at a time" advice worked well for Sanders, who moved her daughter to a bed months before her second child was born. "We gave her a big kid bed early enough that she wouldn't know that was the reason," she says. "We simply told her that she was getting to be a big girl, so we would go shopping for a big girl bed. She was excited and slept in it without any problem from then on."

The Big Switcheroo
As Sanders discovered, it is important to prepare your child for this change in her life. "Make a big deal about getting a new bed," advises Mindell. "After all, it is a major milestone."

Before you're ready to make the switch, start talking about beds. Mention older friends or cousins who sleep in a bed. When you're out shopping with your child, point out "Blue's Clues" or "Sesame Street" sheets. Tell your child how big and grown up he is getting, and talk about some other "big kid" milestones he has reached, such as potty training, giving up a pacifier or dressing himself.

When it's time for your child to make the move, says Mindell, keep in mind that "families go about making the transition in different ways. There is no definite 'right' way." For example, some parents take the child shopping for the bed and new linens, while others buy them as a surprise.

There are also differences in the types of beds parents choose. "We tried one of those whimsical toddler beds shaped like a Volkswagen Beetle," says Pearson. "[My son] thought it was wonderful, and we thought it would make the transition easier."

Sanders chose a regular twin-size bed for her daughter, but started out by putting the mattress directly on the floor. "It eliminated the need for bed rails and, if she fell out, she was closer to the floor," she says. "When our daughter got used to sleeping on the mattress, we put it on the bed frame." Other parents fully assemble a twin bed and use guardrails to keep the child from falling out.

Perhaps one of the biggest questions parents have is whether to remove the crib when the bed arrives or to leave it up for a while. Once again, according to Mindell, there is no right or wrong answer. In this case, you need to consider your child's personality and his tolerance for change.

For some toddlers, out of sight means out of mind, and a "cold turkey" approach will work well. Susan Brannigan-Rampp of Belleville, Ontario used this method for her daughter. "Katie was out with my husband when I brought [the bed] home, so it gave me time to make the switch," she says. "I thought a 'fait accompli' would be the best approach, so I had the crib totally dismantled and put away, with the beautiful big girl's bed sitting in her room, glistening and awaiting her arrival. I also continued to use her crib blanket so she still had some items of familiarity. It worked like a charm!"

Other children may need the security of the crib while they get used to the idea of sleeping in a bed. "We set up the bed a few days before taking down the crib, and let him sleep in the crib for a few more nights while the bed was in his room," recalls Pearson.

Saying "Good Night"
Toddlers love consistency, so keep bedtime routines the same – although you may want to incorporate the bed into part of the ritual. Snuggle on the bed with your child before tucking him in, or stretch out on the bed to read a story.

Mindell advises being careful what you say to your child on that first night in a big bed. "Don't tell your child he's not allowed to get out of bed," she says. "Getting up may not have occurred to him, so don't put the idea into his head." If your child does get up, however, return him to bed immediately and firmly.

Remember that all children eventually adjust to sleeping in a bed – even if the first few nights, or weeks, are bumpy. "Don't force the issue," says Douglas. Let your child make the transition in his own time. Then before you know it, you'll be ready to move on to the next milestone.