LAKEWOOD, Colo. (CBS4) – A device is making its way into schools to hide the smell and smoke of marijuana.

Students are using vapor pens, and they’re using them in classrooms. It’s becoming a problem at Lakewood High School.

“I’ve seen people in my math class and they’ll be sitting there with the teacher and they’ll be smoking it and they won’t even know,” said Jack Maestas, a student at Lakewood High.

Principal Ron Castagna has good things to say about his student body, but he’s not happy to see vapor pens in his school. Staff at Lakewood High know the gestures of vapor pen use.

“Teachers are aware of what to look for. The nervous habit of biting on your pen has a new meaning to it,” Castagna said.

Vapor pen are just like e-cigarettes. The can be purchased at grocery stores for $25.00 and up. When used for marijuana there’s no “skunk” smell, which makes it easy for students to bring them to school.

“You can use them for weed, hash oil. Pens that come with capsules with weed in them, melts the plastic and cooks the weed,” said Tim Martinez, Lakewood High campus security supervisor.

But vapor pens, marijuana, and their use have consequences.

“Would they try to mask it somehow? Yeah. A lot of kids use cologne or vaporizer pens and stuff to cover the smell on their breath,” said Jordan Williams, who was expelled for using marijuana at school.

Williams is clean now and he’s been allowed to return to school.

Vapor pens aren’t the only things students are using. CBS4 was told that students are also using inhalers and edibles to hide the signs of marijuana.

– Written for CBSDenver.com by CBS4 Intern Jaimie E. Goldstein