At a high school in Maryland's capital city of Annapolis, the principal ordered doors removed from bathrooms to keep students from sneaking hits in the stalls.
A school system in New Jersey installed detectors in its high schools to digitally alert administrators to students looking for their next "rip."
And recently in Fairfax County, Virginia, students broke into vape shops looking to score some nicotine.
Those are just some of the consequences school administrators and law enforcement officials across the country are confronting as Juul e-cigarette devices have exploded in popularity among teens. Parents, principals and police struggle with underage use, worried the novelty of the slim e-cigarettes that look like USB drives and their fruity nicotine pods will create a new generation of addicted smokers.
"The problem with the juuling device is they say they are manufactured for adults, but it is manufactured in a way that appeals to children," said Deborah Wheeler, superintendent of the Upper Dublin school district in eastern Pennsylvania. The school system has banned USB memory sticks because students were charging their Juuls with school-issued laptops. "Students don't realize it is still dangerous and harmful to their health."
The FDA shares the alarm, with federal regulators calling the trend "disturbing" as they recently demanded the manufacturer explain why its products have attracted so many minors.
School administrators say the items are insidious because they are easy to hide and virtually smokeless. With nicotine pods that come in flavors including "fruit medley," "cool cucumber" and "creme brulee," the smell that briefly lingers from burning pods can be mistaken for candy or gum.
"The size of these things make it possible for students who are adept at using them to conceal them easily," said Bob Mosier, a spokesman for Anne Arundel County Schools in Maryland. The district includes Broadneck High School, whose principal ordered the doors removed from bathroom stalls that couldn't be seen from hallways.
"We have anecdotally heard stories of students doing it in class," Mosier said. "You can put your hand to your mouth, inhale and blow into your sweatshirt."
Though parents and adults worry the sleek design and fruit flavors are intended to attract minors, company officials said they created the product for adults looking to transition from cigarettes.
"We know adult smokers who want to switch do not want to be reminded of combustible cigarettes," a Juul Labs spokeswoman said in a statement. "JUUL's rectangular shape is a prime example of our intention to develop something different than a cigarette to help current adult smokers switch."
The statement also said that flavors are important for adult smokers looking to quit cigarettes because they don't want to be reminded of tobacco.
"We cannot be more emphatic on this point, however: No young person or non-nicotine user should ever try JUUL," the company statement said.
Sales have skyrocketed since the company launched in 2015. The San Francisco-based firm represents nearly 55 percent of the e-cigarette market, according to data from Wells Fargo.
School administrators, law enforcement officials and health workers said the increase in underage use became particularly marked this year, with students openly posting and sharing photos about Juuling on social media.
"Hate when I see people using the toilets in the JUUL room at school," one person posted on Twitter along side a facepalm emoji.
"you guys need to stop using the big stall in the bathroom to juul because i need to poop," said another student.
The devices cost about $50 each and can be charged through a USB port. Users insert a flavored pod into the unit and simply take a draw to start smoking. Each pod - roughly $20 for a box of four - contains about the same amount of nicotine as a pack of cigarettes.
Jenny Sexton, a substance-abuse counselor for Arlington County schools in Virginia, worries students may mistake the fruity flavors of the Juul pods for a benign product, when they're actually filled with nicotine and can be reloaded with THC oil (an extract of marijuana) or unregulated substances.
"The youth will share them and they use this and we're concerned that they're consuming something with high levels of nicotine and may not be aware of it," Sexton said.
In a survey that the tobacco-free Truth Initiative conducted of 15-to-24-year-olds, a quarter of respondents recognized a Juul e-cigarette when shown a photo of the product. But 63 percent of users didn't know the product always contains nicotine.
Sexton tells parents to monitor their online shopping accounts and credit cards in case children have been buying the products without their knowledge including at the many online shops that simply ask customers to check a box saying that they're over 18.
Mark Lamagna, a manager at Vape Ink in Rockville, Maryland, said about 100 teens try to come into the store each week, mostly to buy Juuls. The store, in a strip mall near Richard Montgomery High School, trained employees to check for IDs, spot underage customers and be on the lookout for fake driver's licenses. Lamagna said often times the students, who tend to show up at the store in big groups, end up leaving after employees ask them to present identification.
"The kids that have school hoodies on or anything like that we definitely have to check ID," Lamagna said.
But, when it comes to adults, Juul is "appealing mainly because a lot of people are trying to quit cigarettes and it's hard to imitate the way it feels," in products meant to wean them off, Lamagna said. "For the most part Juul has taken a step up and made it so it would be pretty similar to an exact hit of a cigarette, but without the carcinogens and without the harmful chemicals."
There is little solid research covering the long-term effects of e-cigarette or Juul use, but health officials are concerned because the products still contain nicotine and could eventually get underage users hooked on traditional cigarettes, according to the Campaign for Tobacco-Free Kids.
Sgt. Brett Choyce, who supervises school resource officers with Fairfax County police in Virginia, said officers work with the school district to talk to students about the consequences of nicotine addiction.
"It's one of the most addictive drugs there is," Choyce said he tells students. "Once you're hooked ... you're giving yourself a lifetime crutch."
Officers also warn students who are caught Juuling and sent to school drug-diversion programs against inhaling mystery substances.
In April, the U.S. Food and Drug Administration launched a massive undercover effort to crack down on underage sales, issuing 40 warning letters to stores across the country including one in Frederick County, Maryland. In addition to the undercover operations, the FDA announced it is requiring Juul to submit its product research and marketing studies to understand why teens are drawn to the brand.
"We're going to be taking more actions going forward as the blitz continues," FDA Commissioner Scott Gottlieb said.
The company quickly responded by announcing it would dedicate $30 million to research, education and prevention efforts to keep its devices away from young people.
But some parents say those actions have come too late.
At an Arlington County town hall on substance abuse, frustrated parents recently demanded answers to how officials plan to keep Juuling out of schools.
One mother of two teenage daughters at Yorktown High School said her children have started Juuling and get offered hits every day.
"If my daughters could have the Juuls turned off during high school, their exposure would be down 99 percent," said the mother, who asked not to be named to avoid identifying her daughters.
At the town hall, portraits of those in the community who died of drug overdoses flashed on a giant screen above the stage - a brother, a football star, teens in caps and gowns.
The mother and other parents in the audience feared that students starting to use Juuls would eventually become addicted to substances like the drugs that took the lives of those up on the screen.
"They text each other: 'You want a hit in the bathroom? Second floor,' " the mother said of students at her daughters' high school. "I'm worried about them."