35-Month-Old Child

Like rocking and head-banging, hair twirling is a self-comforting behavior that toddlers use to release pent-up energy and tension.

Hair twirling (and even the more aggressive hair pulling) can spring up around the age of 3, and tends to occur at night, when children wind down for the evening. In most cases, the habit is nothing to worry about, and forcing your toddler to stop is only likely to backfire.

Instead, try giving him another outlet to relieve his stress — a toy hammer to pound or a toy drum to bang — or implementing a soothing bedtime routine (a quiet bath, a book and soft music). And if all else fails? Go for a super cropped haircut. Short hair is a lot harder to twirl!

Are you a parent of two (or planning to have more than one kid)? Then it’s likely that by the time a child is 11 years old, he’s spent about a third of his free time hanging out with his sibling.

All that time spent together has some benefits: Research shows that having a sibling may lead to less depression, more life satisfaction, more self-esteem and, among daughters, a lower risk of obesity.

As an adult, kids who have a brother or sister may also be less likely to divorce. Turns out, navigating life with a sibling may be good training for negotiating the ups and downs of marriage.

Moving your toddler from a nursery to a big kid room is, well, a big step. To get your child excited about the transition, let him take charge of some of the decorations.

Ask him to pick out some fun sheets, whimsical pillows or stuffed animals, which you can incorporate into the room.

There’s no need to go all-out with superhero- or princess-themed everything, though — a framed poster here and a plastic crown there should suffice for now (and will be easy to change out when he moves on to the next phase).

You can also incorporate a few more grown-up features into his room, like an open, kid-friendly wardrobe, a kid-sized table and chairs, and even a colorful wall mural.

Chances are, your child’s first and second birthday parties were relatively apolitical affairs, with the guest list limited to family and a handful of friends. But once your child is in preschool, there are more kids to consider.

While you don’t have to invite the entire class (unless there are school rules in place), you should avoid leaving out just one or two of his classmates. If you’re not inviting the whole class, don’t hand out invitations at school — email them instead.

You also don’t have to open gifts at the party itself. Toddlers aren’t always gracious about getting presents (“I don’t like this toy!”) or watching other kids get them.

Losing a pet is hard for anyone, but it can be especially tough on a toddler, who doesn’t quite understand the concept of death.

Although it might seem easier to tell a white lie — “Lulu ran away” — you don’t want to have to keep lying to him or get his hopes up that your pet might return. In this case, honesty is the best policy: Explain as gently as possible that Lulu died, and isn’t coming back.

While it may seem harsh to say this directly, using a euphemism, like “Lulu went to sleep” or “Lulu went away,” could backfire: You don’t want your child to think that you won’t wake up after going to sleep or leave the house without coming back.

Accidents are unavoidable when you’re teaching your child to use the potty. But sometimes, a child who has been potty trained will suddenly start having accidents all the time or even want to go back to wearing diapers altogether.

In this case, you may need to sleuth out the cause of the regression. Stress — over a new sibling, sitter, house or day care — may be to blame, as can parental pressure to use the toilet.

Toddlers can also be prone to excitement, which can trigger an accident, or too busy to notice an urge to go. Still other tots simply don’t want to stop what they’re doing until it’s too late.

To right the ship, go back to the basics: Suggest regular bathroom breaks first thing in the morning, after a meal and before bed, and re-institute the sticker or M&Ms reward system.

From the ages of 3 to 5, many toddlers develop a case of the “gimmes.” That doesn’t mean they’re “greedy,” though — it simply means that they lack the ability to delay gratification.

While you don’t have to cave to your toddler’s every demand for the next few years, you may be able to avoid a meltdown by telling your child that you’re “only buying food at the store today, not toys.”

If he sees something that he must have, tell him you’ll add it to his birthday or holiday wish list, or suggest that if he still wants it next week, you’ll consider buying it. (Chances are, he’ll forget about it by then.)

Remember: It’s good for a child to hear an occasional “no” — after all, he has to learn that people don’t always get what they want, when they want it.