It's a startling statistic: almost half of 7th to 12th graders experienced some kind of sexual harassment during the 2010-2011 school year.

The American Association of University Women surveyed a nationally representative group of almost 2,000 students. They defined sexual harassment as "unwelcome sexual behavior that takes place in person or electronically."

Overall, 48 percent of students surveyed said they were harassed. Girls reported being harassed more than boys - 56 percent to 40 percent - but it was more evenly divided in middle school.

Many students experienced negative effects as a result of the harssment. Eighty-seven percent of those who were harassed reported experiencing poor sleep, stomachaches, and even staying home from school.

The report comes at a time when bullying and cyber-bullying in schools is in the spotlight, after several students committed suicide nationwide.

This study highlights cyber-sexual harassment, since many kids reported that they experienced sexual comments and online rumors on Facebook, through texting or by email.

When asked what types of students were most at risk of harassment, students said pretty girls, ugly girls and feminine boys were the most likely targets. Interestingly, half of students who were harassed did nothing about it; they thought reporting it would not have any impact or might even make the situation worse.

This survey shows sexual harassment is really an epidemic in schools. "It's pervasive, and almost a normal part of the school day," said one of the report's authors Catherine Hill.