Zach Lewis swears he was just resting his eyes.

But when a fellow student at Stowe Middle High School in Vermont surreptitiously snapped his picture during English class and shared it with the school’s “sleep account,” it was hard to dispute the evidence. There he was, book open, lids shut.

After Zach was tagged in the photo on Instagram, he sent a message to the people who manage the account to remove it. They quickly deleted it. “I wasn’t worried about a teacher seeing it,” Zach, 16, said. “It’s just embarrassing to have it up there.”

But that didn’t stop him from secretly photographing another student who fell asleep in English, then submitting it to the account for publication.

“Everyone,” Zach said, “has been trying to catch each other.”

Part prank, part extracurricular documentary project, sleep accounts are among several types of so-called school accounts that have proliferated on Instagram in recent months, as students have returned to classrooms following two disrupted academic years. After many months of pandemic-mandated remote instruction, teenagers have come to regard such banalities as their classmates eating, slouching and parking badly as fodder for amusement — and, of course, content.

“Now that we’re all in person again, we realize there are so many things we missed out on seeing last year,” said Ash Saple, a 17-year-old junior at Hamilton Southeastern High School, in Fishers, Ind.

At Ash’s school, there have been accounts capturing good parkers, bad parkers, cute outfits, shoes, fast walkers, slow walkers and red-haired students. Compared to the spicy rumors shared by fictional students (and teachers!) on “Gossip Girl,” the images are rather tame. (Even when you take into account the odd accounts that delight in showing students’ feet under bathroom stalls.)

Ash herself runs an “affirmation” account, where she makes and posts funny, glass-half-full memes that play on her school’s inside jokes and culture. Her first post showed a car parked off-center in a school lot. “I will not end up on @hsebadparking,” the affirmation read.

The students behind these accounts say they are mostly a harmless trend, predicated on the novelty of being in the same physical space as their classmates again. There is also a poignancy to the accounts; as many students head out for winter break amid a national surge in Covid-19 cases, there is some uncertainty about whether in-person instruction will resume in January.

“On your computer in your bedroom, you can’t see people napping and you don’t see how badly people park their cars because no one left their house,” Ash said. “There are so many things that you forget about that are just normal things that we’re now able to notice.”

The account that posted the photo of Zach appearing to doze off in class in Vermont is run by two sophomores, Teague Barnett and Andrew Weber, both 15. They had seen on Instagram and TikTok that other students at schools had started slouching and “bathroom feet” accounts.

They decided to create one themselves: a sleep account in which anyone who wished to have their photo removed would be respected. “There is a high school cliché that everyone is falling asleep in class and this account is here to poke fun at that,” Andrew said.

The boys see it as a lark. “A lot of the things that are fun to high schoolers are risqué and things parents wouldn’t be OK with,” Teague said. “But this is a good way to escape and play a little prank and no one is getting hurt.”

Parents seem to agree. “It’s great to have the kids back in school and able to poke fun and have a good chuckle,” said Andrew’s father, Chris Weber. He sees it as a reflection of a generation that has grown up with smartphones and social media, observing and being observed.

“They document their entire lives,” Mr. Weber said. “And they’re very comfortable being seen by their peers at almost any moment.”

Jacqueline Montantes, a 16-year-old high school sophomore in Seguin, Texas, was recently featured on her school sleep account after a long night of studying. She’d made it through history class, but algebra II did her in.

When she saw the picture on her school account, she thought it was funny. “But I was scared my coach was going to see it,” said Jacqueline, who is a member of the Seguin Starsteppers, a drill and dance team. (If the coach saw it, she didn’t say so.)

Later, she made a TikTok that showed some of the sleeping photos from the account. “Can’t even be comfortable in class anymore,” she wrote in the video’s caption.

That sense of being constantly monitored has also hit Maggie Garrett, a 15-year-old sophomore in Atlanta. “I think it’s fun, but it keeps everyone on edge,” she said. “No one wants a bad picture of themselves slouching or sleeping or eating being posted.”

Last month, Maggie made a video of her and her friends, sitting with ramrod posture at a lunch table at school. She shared it on TikTok with the caption, “Us trying not to get posted on our schools slouchers Instagram account.”

“It got quite a lot of notice,” Maggie said, “and my friends were like, ‘Oh my gosh, I’m featured on a TikTok that’s getting a lot of views.’”

At least they were sitting up straight.