Police drug dogs are trained to hunt the smell of drugs
Retired sniffer dogs that have spent years on police patrol are now working in the private sector in the US - sniffing out teenagers' bedrooms.
Parents can rent a dog and handler for $200 (£125) an hour from Sniff Dogs, a firm operating in New Jersey and Ohio.
The dogs are highly trained and can detect illegal drugs.
The company says the animals can smell marijuana from up to 15 feet away (5m) and residue on clothing from drugs smoked two days earlier.
The dogs sit when they detect the drugs but they leave the final inspection to the parents.
The company was founded by a mother of two sons, who was surprised to find her oldest son smoking marijuana.
Sniff Dogs claims to offer a "discreet service" that avoids the confrontation that comes from drugs tests because the search can be carried out without the knowledge of their children.
The company cites statistics showing half of American schoolchildren have tried marijuana and that most drug taking takes place when they get home from school.
Pat Winterstein from Washington, New Jersey decided to use the service to search the bedrooms of her three children.
"I trust my kids, but you only can trust them so far. They're kids, young adults, they're going to make (a) mistake," she told ABC news.
Critics claim that the service could be invasive and may break down family trust.