Many of the signs of cyber bullying are similar to those of traditional bullying, and it can be difficult to pinpoint the difference between normal moody kids and their growing pains and the start of a serious problem. It is important to watch for a change in your child's behavior that isn't attributed to normal developmental changes.

If your son normally loves to send instant messages to his friends but suddenly starts to resist using his computer and disables the IM feature when he does go online, it's time for a talk. If your son seems grouchy and upset after playing an online game with friends or deletes his e-mail without opening it, there might be a problem. Parents need to tune in and watch for unusual behavior or responses that happen in conjunction with computer use.

It can be difficult to get your child to open up about any abuse or mistreatment he is receiving. Older kids may feel that they can handle it on their own, they may be embarrassed to tell you what is happening, or they may be concerned about how you will react. Denial is likely the first line of defense.

As with traditional bullying, studies show that the best time for intervention is when the online bullying first starts. Many kids can successfully stop the bullying if they are supported, coached, and assisted in their efforts.

Unfortunately, the longer it continues, the harder it is to stop. So the first step for you, as a parent, is to be on the lookout for any of these signs:

• Your child might experience a sudden loss or increase in appetite, have stomach aches or headaches, or sleep disturbances (these are stress-related symptoms).

• Your child might become secretive and try to hide his computer communications from you. Watch for signs of excessive deleting, emptying of the deleted folder, or erasing of the history file. Or he may rapidly switch screens when you are near.

• Your child may be angry, sad, or depressed after spending time online, after a cell phone call, or after receiving a text message.

• Your child may act moody, sullen, or withdraw from family interaction.

• Your child may put himself down and say things like, “I'm stupid.” “I have no friends.” or “I would be better off dead.”

• Your child might seem overly concerned with personal safety issues.

If you see any of these signs, tread lightly, but do try to get to the bottom of the situation. Kids tend to keep traditional bullying a secret, and studies are showing that online bullying might be reported or revealed even less often.