All parents wish that their children are perfect little angels who go to bed on time and listen to instructions without creating a fuss. But the reality is that some kids are naughtier than others and find it difficult to break free from bad habits.

To help parents, doctors and health experts shared with Fox News some tips on how to stop a child from nose-picking, thumb-sucking, and other bad habits.

A lot of kids like to suck their thumbs or fingers to soothe themselves, but the growth of their jaw will be affected when they continuously do so. Dr. Jade Miller, president of the American Academy of Pediatric Dentistry (AAPD), said this habit can affect the normal growth of the upper jaw, making it grow narrowly and cause a crossbite or overbite.

To discourage kids from this bad habit, Miller said parents should apply on their kids special nail polish that tastes bitter, let them put on a cotton glove or finger guard. Sometimes praising the child for not putting his fingers in his mouth also does the trick. "In many cases, kids will stop on their own," Miller said.

Another thing parents need to help their kids outgrow is teeth grinding. Miller said around 14 to 20 percent of kids grind and clench their teeth, and it's common when new teeth come in or whenever kids are feeling anxious or stressed.

She recommended that parents take their kids to a paediatrician or a dentist so they can place a mouth guard and protect the child's permanent teeth.

Even though parents don't like to admit it, their kids probably pick their nose on occasion. Kids do so whenever their noses are filled with boogers. It gets worse whenever they have a cold, congestion or allergies. Dr. John P. Dahl, a paediatric otolaryngologist at Riley Hospital for Children at Indiana University Health in Indianapolis, Indiana said parents simply have to be persistent in keeping their kids' noses clean and to remind them that it's unbecoming to have their finger in their nose.

Whenever kids have colds or infections, a salt water saline spray or gel can significantly help clean the nose. As for babies, Dahl said parents can use a bulb syringe.

Meanwhile, a lot of parents struggle with picky eaters. Most kids ignore vegetables and choose to eat only a handful of foods. Dina Rose, PhD, a sociologist, parent educator and feeding expert in Jersey City, New Jersey and author of "It's Not About the Broccoli: Three Habits to Teach Your Kids for a Lifetime of Healthy Eating," said picky eating can cause a lot of stress at home.

"Because kids eat multiple times a day, this becomes more of a stress point in the family dynamic than other problems," she said.

The trick here, according to Rose, is to make their kids excited about healthy eating. Rose suggested that parents serve pea-sized amounts of new foods so kids will feel safe and empowered enough to eat them and accept them. And instead of asking, "Do you like it?" Rose said parents should try asking about the smell, feel, or texture of the new foods. 

"The goal becomes to teach children about food and not from a nutrition perspective but from a sensory perspective," Rose said.