The hurtful words, acts and even physical harm that can accompany bullying are often learned behaviors, and some parents are unaware their child is intimidating others until they receive a phone call from school, said Bill Voors, director of the Midwest Bullying Prevention Project.

"Don't take it as judgment," he urged parents. "The school is on your side. Be part of the partnership."

Even if the bullying seems mundane now, it can escalate quickly and become much more difficult to deal with later, experts said.

A study by Vanderbilt University found that 60 percent of boys who bullied between sixth and ninth grades were convicted of at least one crime by the age of 24, while 40 percent had three or more convictions.

Contrary to popular belief, bullies are not necessarily the insecure tough kids, experts said. Studies show there are now just as many girls as boys who bully, and these children can be very confident and well-liked with lots of friends.

A child may bully based on physical strength, social status and intimidating behavior, including aggression, dominance, demands to always be the leader and lack of empathy, experts said.

Carlabeth Mathias, a certified licensed social worker who counsels bullies, said parents should watch for how children interact with others, even at an early age.

"If you see these behaviors, you need to sit down and talk to your child about them and the affects of those behaviors on other people and themselves," she said. "Help your child replace the negative social behaviors they're exhibiting to more pro-social ones that are acceptable."

She advised parents to listen to their children, not judge, and teach them empathy, respect and compassion. She said it's key to let children know that there are consequences for violating expectations.

6News will have a series of stories this week addressing the issue of bullying among children.