SÃO PAULO — Bedtime is the most difficult time of day here. They can't decide whether to stare at the ceiling, hum the latest pop hits or simply close their eyes and wait for sleep to take them away.

In the morning too, it feels strange. Nobody has a watch, so even the time eludes them. When they leave their bedrooms, many of them still reach for their smartphones in their pockets, before remembering that all Internet devices are banned here.

With the end of the summer break approaching fast, a growing number of holiday camps in the Brazilian state of São Paulo are making this their rule. Their goal is to encourage teenagers to spend days connected to the people around them, not to their social networks and electronic games.

And parents who can afford it are willing to pay a lot of money for their offspring to undergo this "digital detox" — away from Facebook, Candy Crush and selfies. A one-week holiday camp like this can cost up to 3,800 reais ($1,500), considerably more than the country's average monthly wage, which is barely $1,000.

"If at least we could take selfies in the bathroom, I wouldn't mind so much not having access to the Internet," says 13-year-old Laura. Laura is a self-described digital "addict," but she can see the benefits in living offline for a while. "If I wake up at 7 a.m., I normally stay on my tablet until 11. But here I can do so many things in that time!"

Mud run at a digital detox near São Paulo — Photo: Guilherme Pires via Instagram

As soon as she arrived at the camp, Laura met Giovanna, a 12-year-old girl from São Paulo. The two have been inseparable since. But had Giovanna been allowed to take her new iPhone 6 with her, things could have been very different: "I would have cut myself off," she explains.

At the camp, adults are trying to reignite the children's sense of adventure. During a hike, for example, a camp counselor asked them how to find north. The answers he got weren't quite what he might have expected. "Let's just check on Waze (a community-based navigation app). Please turn right," a boy joked, imitating the app's voice. "Turn the GPS on," said another.

But two or three days are enough for the "detox" to really work. All of a sudden, games that have formerly fallen out of fashion — jumping rope, garden cricket or simply running in mud — gain a newfound popularity. "We play cards, dance with hula hoops," says Marcelo, 15. "Things that our digital generation didn't even know existed."

There are exceptions, teens who can't or won't embrace the spirit of the camp and who eventually ask to leave. But camp managers say these cases are few. Those who suffer the most are actually the parents, who sometimes feel guilty for sending their children there.

The counselors say they often have to call children via the loudspeaker, at the risk of embarrassing them, because their "desperate" parents want to talk to them. To help them cope, one camp has agreed to print emails from parents and give them to their children. But most teens respond in a way that parents have heard all too often: "I'm busy."

With or without their smartphones, kids will be kids.