More than 600 students at Highlands Elementary School are being checked for head lice following 11 reported cases since the end of October, school officials said Thursday.

Five classrooms and four grades have students with head lice, Principal Paul Martinsen said.

While lice are typical in schools, Martinsen called the current situation uncommon given the high number of cases.

Keith Karzin, director of safety and risk management for Saugus Union School District, said cases of head lice happen from time to time.

"It happens basically in all schools, not just Saugus Union," Karzin said.

Lice live in between human hairs and feed on small amounts of blood from the scalp, according to kidshealth.org.

Lice are not considered dangerous and do not spread disease, according to the Web site.

The school sent a letter home to Highlands families last week informing them of the situation and precautions for parents, Martinsen said.

People who have lice have to wash everything from their clothes and linens to get rid of the tiny, wingless parasitic insects. Kids need to use a special shampoo and treatment procedure to kill the insects and their eggs.

Even common-use areas like sofas and head rests in cars must be scrubbed.

The Saugus school is also being cleaned.

"Everything is getting wiped down on a daily basis," he said. "That has been happening all year long because of our concerns with the flu outbreaks."

School nurses and health assistants have been checking all 607 students for lice.

"If they're found (to have lice), the students are sent home," Karzin said.

Students are not readmitted back into school until the lice are gone, he said.

Karzin said part of the problem is that lice have the ability to spread quickly because kids are so close to each other in school.

"If you've got kids that are close to each other, sharing combs and brushes, that's how this could be passed around," he said. "It starts with one individual and it could spread from there."