Forty-eight percent of US middle and high school students suffered sexual harassment in the past school year, both in person and online, a national survey released Monday said. And 87 percent of those students said the experience had a negative impact on them, according to the survey of 1,965 students in grades seven through 12 conducted by the Association of American University Women (AAUW). "Sexual harassment is part of everyday life in middle and high schools," said the 76-page report, which follows the Washington-based charity's previous investigation of bullying in schools. "Sexually harassed students who took part in the AAUW survey reported having trouble studying, not wanting to go to school, and feeling sick to their stomach," it said. Some students stayed home from school. Others skipped classes, dropped after-school activities, took different routes to and from school, or changed schools altogether. Yet only nine percent ever reported incidents to their teachers or guidance counselors, said the report, which called upon educators to be more proactive in addressing the issue. "For some students, understanding that sexual harassment can indeed be a big deal for other students is a necessary first step," the report said. Girls were more likely to be sexually harassed than boys by a wide margin of 56 percent versus 40 percent, both in person and through emails, social media or text messaging. Thirty-three percent of all respondents said they had been the targets of sexual comments, jokes or gestures, and 13 percent of girls -- and three percent of boys -- reported being touched in an unwelcome sexual way. Equal numbers of boys and girls (18 percent) reported being called gay or lesbian in a negative way -- and being called a lesbian was particularly common for girl athletes. The survey also looked into the motivations of students who sexually harass other students. Forty-four percent said that such conduct was just a fact of school life; 39 percent said "I thought it was funny" and 34 percent said "I was being stupid." Twenty-three percent were motivated by revenge. Middle school in the United States is generally understood to be grades six through eight, or ages 11 to 13, and high school as nine through 12, or ages 14 to 18.