They become isolated, un-talkative, and obsessed with Led Zeppelin IV

While not a dead giveaway, your teen’s anti-social behavior and sudden fascination with the 1971 Hard-Rock classic Led Zeppelin IV could mean that they’ve accidentally seen a few classmates doing drugs in the school parking lot.

No need to panic. As hard as it may seem, when they march straight up to their room without saying a word and start blaring Jimmy Page’s timeless riffage on “Black Dog” it’s best to let them have their space. Kids need to vent, and if yours is channeling their feelings through an album that has come to define 1970s drug culture, it’s likely a normal, natural response to having watched some other parent’s kid do drugs.

They come home late and eat multiple bowls of cereal in the dark

If your kid doesn’t even bother to flip the kitchen light on before wolfing down an entire box of Fruity Pebbles, they’ve either secretly joined the swim team or just came back from a long, tiring night of watching other people’s kids do drugs. Don’t jump to any conclusions yet. Confronting your child too soon can make them defensive. Keep an eye out for them and try to be understanding, after all, watching other people’s kids do drugs can be a confusing time for your teenager. Give them the benefit of the doubt for now and allow them to devour 4-5 bowls of cereal in the darkness—their eyes are probably tired from watching their peers make all sorts of poor decisions.

They begin to make angsty yet insightful comments on American society at the dinner table and always smell like drugs

It’s well known that other peoples’ drug-addicted children often rebel against traditional ideas and smell like drugs. So, if your teen shows up to dinner reeking of smoke and saying things like “the way the Bush administration handled the crack epidemic was totally stupid” and “cable news outlets are beholden to corporate advertisers, you bitch,” it may indicate that your teen has repeatedly witnessed some drug use. Seeing those slimy no-good kids choose to get high just a handful of times can cause even the best and brightest to become smelly and radicalized.

To be sure, it’s good to wait and see if they jump up from their chair and shout, “You are a slave to material wealth. I hate this house. I hate you. I’m going over to Sage’s place.” This isn’t a tell-tale sign, but you should always be aware of how another parent’s degenerate child may be affecting your kid’s scent and perception of the world.

You find a bag of drugs in their sock drawer

Parents, it’s time to make a tough decision. You’ll want to be careful in the way you approach your child about what they’ve seen other parents’ kids doing. Start by throwing out some names (Was it Caleb Holmes? He always seemed like a bad influence. Jimmy from down the street? His mother is kind of damaged goods, huh?)

Remember, just because your child is watching people destroy their brains with drugs right now, doesn’t mean they’ll end up watching other parents’ kids go to prison, overdose, and die as an adult. The most important thing is to let them know you’ll be there when they are ready to tell you who they’ve been watching do all these drugs.

You get home from work early and they’re sitting in a circle of kids that are doing drugs

There comes a moment in every parent’s life when they must face some harsh reality about their child; all their classmates are having sex, someone has forced them to want to go to art school, or, they’ve brought friends into your home for the sole purpose of watching them do drugs. If this happens, draw a line in the sand. Let them know that observing drug use in the house will not be tolerated. As punishment, make your kid watch you do all of the drugs in a single sitting. Watching other people do drugs won’t seem so much fun then, will it?