It’s a common scene at your house: your teen has her head buried in her phone. Gone are the days when a teens' social life existed only in school hallways , the mall and friends’ houses. But as their social lives have moved online, so has a new kind of bully.

Cyberbullies use the internet, cell phones, video game systems, or other technology to send or post text or images intended to hurt or embarrass another person. They so this by threatening, excluding, spreading rumors or tricking their victims.

According to data from the National Crime Prevention Council (NCPC), 43 percent of teens have been victims of cyberbullying in the last year.

In some ways, cyberbullying can be more damaging than physical bullying. It can be harsher. People tend to be crueler online than they are face-to-face. It can be far reaching. With a few clicks, a bully’s message can reach the whole internet. What worse, cyberbullying has invaded the comfort and safety of our homes. And, your teen may not even know who the bully is.

How do you know if your teen is being cyberbullied? The biggest red flag is a withdrawal from technology. If you notice a sudden change in your teen’s computer or phone usage, talk to her. Kids who are being cyberbullied often feel too embarrassed to speak up.

Be on the lookout for these warning signs that your teen is being cyberbullied:

• Suddenly avoids the computer, cell phone or other devices
• Exhibits low self-esteem or depression
• Is extremely moody, agitated or anxious
• Appears stressed when receiving an email, instant message or text
• Changes in eating or sleeping habits (e.g., nightmares)
• Withdraws from family and friends
• Doesn’t want to participate in activities he/she once enjoyed
• Suddenly changes friends
• Doesn’t want to go to school
• Has declining grades or gets into trouble at school
• Hurts self, attempts or threatens suicide

Parents can take steps to prevent cyberbullying before it starts or becomes worse. The National Crime Prevention Council (NCPC) offers these tips to keep your teen cyber-safe:

• Keep your home computer in a common area of your house.
• Set up your teen’s email and chat accounts with them. Make sure you know their screen names and passwords. Tell your teen to never share passwords with anyone except you (not even their friends).
• Communicate online rules and responsibilities. Almost 80 percent of teens said that they either did not have parental rules about internet use or found ways around the rules.
• Monitor your teen’s online usage and behavior. Regularly go over their "buddy list" with them — ask who each person is and how your teen knows him or her.
• Share examples of inappropriate incidents that can happen online, which teens may view as harmless or normal. Tell your teen to never arrange a face-to-face meeting with someone he/she met online.
• Remind your teen to never give out personal information online (including names, addresses, phone numbers, school names, credit card numbers, etc.). Point out that the internet is accessed by millions of people all over the world, not just friends and family.
• Tell your teen not to put anything online that they wouldn't want others to see, even in email. Remind them not to send messages when angry or upset.
• Tell your teen to never open emails from someone he/she doesn't know or from someone they know is a bully.
• Tell your teen that it’s not his/her fault if they are cyberbullied, and you won’t blame them or take away their computer privileges. (This is the main reason kids don't tell adults when they are cyberbullied).
• Teach your teen not to respond to cyberbullies. Show them how to block the bully’s messages or to delete messages without reading them. Over 70 percent of teens said that being able to block cyberbullies was the most effective method of prevention.
• Help your teen keep a record of bullying incidents. Let her/him know that cyberbullies can often be traced, located and punished. If the cyberbullying involves threats and harassment, report it to the police.

How do you raise a kind kid, not a bully? Bullying is learned. This means it can be unlearned or prevented. Learn how to not raise a bully.

Are you worried your child is a victim of cyberbullying? Explore behavioral health resources, including counseling and programs for adolescents.

October is National Bullying Prevention Month. Learn how to get involved.