While under Colorado law marijuana use is legal for adults, it is still illegal for people under the age of 21 to consume it and the state is launching a new campaign to try to prevent teens from using it. According to the Denver Post there is a $2 million campaign with a message of “Don’t be a Lab Rat.” From the Denver Post:

The campaign will feature a handful of human-size rat cages — complete with attached giant water bottles — scattered throughout the city and festooned with posters bearing the campaign’s messaging. One poster, for instance, will read: “Volunteers needed. Must have a developing brain. Must smoke weed. Must not be concerned about schizophrenia.”

The television and movie theater spots have a similar tone. In one, teens are shown lighting up in a smoke-filled car. Text on screen tells of a Duke University study that argued teenage marijuana use causes lasting drops in IQ.

“Some dispute that study,” the text continues. “But what if, years from now, you learn they were right?”

Only time will tell how effective this particular campaign strategy will be, but this is an important reminder that something can still be legal for adults and still strongly discouraged for children. Tobacco is a perfect example. It is still legal but successful messaging campaigns have helped youth cigarette consumption drop significantly over the past few decades.

Despite the scary tactics of prohibitionists, permitting adults to legally consume marijuana doesn’t mean use will skyrocket among teens. A recent study found states legalizing medical marijuana didn’t increase use among high school students. Similarly, The Colorado Department of Public Health and Environment survey of teens in the state found teen marijuana use actually went down slightly since voters approve Amendment 64.

Jon Walker is the author of After Legalization: Understanding the future of marijuana policy