Logan Mitchell, a senior at North Hall High School, said vaping nicotine on campus is common because it’s so easy to disguise.The vape liquid can be odorless, or smell like potpourri, unlike the distinct, clinging smell of tobacco smoke. And the device itself is easy to hide in a pocket or purse. But because it’s so easy to conceal, it also means vaping is out in the open, with students known to vape in classrooms, bathrooms and elsewhere on campus.