Unfortunately for parents, children often won’t tell when they’re being bullied, whether they’re embarrassed or fear either retaliation or escalation. But there are signs parents can watch for, including:

A sudden change in personality, including loss of appetite, unexplained mood swings, uncharacteristic anger, social withdrawal or acting out. If your normally gregarious child is withdrawn and quiet, ask him what’s going on. Bursts of anger may also tell a story – if your child suddenly begins throwing fits or acting out, find out if he’s being bullied at school.

Daily stomachaches or headaches or a refusal to go to school. Kids that are bullied begin to invent ways to stay at home to avoid the bullying. If your normally healthy child has stomachaches, headaches, or other excuses, first be sure that he isn’t actually sick. Then, ask why he doesn’t want to go to school.

A drop in grades or loss of interest in schoolwork, especially if your child is gifted. If your smart child is suddenly neglecting his homework and other schoolwork, there’s a problem. Chat with teachers and administrators (without embarrassing your child) to find out what’s going on.

Frequent requests for more lunch money or missing items (like backpacks, shoes, electronics). If your child is asking for more lunch money, it could just be because he wants to get an ice cream after lunch. It could also signal that someone is stealing his or taking it from him. Ask your child outright, and give him some ways that he can stand up for himself. If you notice your child’s calculator, favorite shoes, or video games missing, ask where they are. If you think your child is lying, get to the bottom of the story and find out where the items are.

Unexplained scratches or bruises, or torn or soiled clothes. If your child is being physically harmed at school, the school should intervene. If the bullying is occurring on the bus, walk home from school, or on the playground, teach your child how to get help.

Certain types of children are also more likely to be targets of bullies. Sadly, special-needs students can be picked on for their differences, whether physical or social. But researchers believe any child who is particularly sensitive, lacks social boundaries, has low self-esteem, fails to defend himself or, especially, does not have a peer group is more likely to be bullied. Bullies pick targets that are either passive or easily provoked.

Your child is secretive or hides his phone or laptop from you. Children who are being cyberbullied often pay fierce attention to what’s going on on the screen. If your child is going to bed with his cell phone, refusing to let you see the phone, or staying up all hours of the night, it could be signs of a problem. If your child is being cyberbullied, find out how you can stop it at the National Crime Prevention Council’s website.