Oddly enough, children this age don't turn their nose up at napping because they suddenly need less rest -- changing sleep patterns are the real culprit. "A baby's urge to sleep builds up faster than a toddler's or preschooler's, so a baby gets tired earlier in the day," says Dr. Owens. By the toddler years, a child's urge to sleep earlier in the day weakens, allowing him to stay awake longer. Consequently, your child's need to nap may come and go as his body adjusts to a more adultlike sleep pattern. But biology isn't totally to blame here -- there are a few temporary factors that trigger naptime battles.
Growing independence. Toddlers love to be in control, so it's no surprise that they'll refuse to sleep on your command. Plus, kids this age are so active and curious that they hate the idea of taking a snooze break ("What if I miss something exciting?").
Scheduling conflicts. The naptime at your toddler's daycare or preschool may not coincide with the hour your child typically gets tired. If he's at home, his ideal naptime may conflict with a sibling's schedule or your daily routine.
Lack of sleep. It's hard to believe, but overtired kids may have trouble falling asleep. That's because when toddlers get tired, they often become irritable and hyperactive, says Dr. Owens.
A major change. Any stressful event -- moving to a new house or switching to a big-kid bed, for example -- may make your child feel too anxious to doze off easily.
No matter what's got your toddler's nap schedule out of whack, your main concern is to ensure that he gets enough sleep in a 24-hour period, says John Herman, PhD, professor of psychiatry and pediatrics at UT Southwestern Medical Center, in Dallas. When he logs those hours is less important. In fact, many toddlers who stop napping during the day will compensate by sleeping longer at night anyway.
Unfortunately, it can be tricky to figure out how many hours of sleep your toddler needs, since the answer depends entirely on your child. "Studies show that at age 3, for example, kids need anywhere from 10 1/2 to 15 hours of sleep," says Dr. Owens. "The average is around 12 hours, but some kids need more and some need less." Your child's behavior is your best clue: If she wakes up spontaneously in the morning and is generally in a good mood, she's probably getting plenty of zzz's.