The call to IT was a strange one. A cochin rooster had accidentally changed a password on a cash register, and someone needed to come and unlock it.

“We had to explain the situation—a chicken changed the password, and we don’t know what it is and he’s not giving it up,” said Sue Cristante, the fluffy bird’s owner. She had brought her pet chickens into work and dressed them up as bumblebees to help advertise that shoppers at the Ontario, Canada, hardware outlet Peavey Mart could now purchase beehives. “It took them a while to respond.”

At the store, Cristante, 56, lends her expertise to customers who are building their own flocks. Pre-pandemic, the company probably sold one chicken coop per year. “Now we can’t keep them in stock,” she said. “Chickens have really caught on.”

In the U.S., the $30 billion retailer Tractor Supply is hoping to capitalize on how much people have grown to treasure their chickens. While they often come to chicken-keeping as a way to live a more sustainable lifestyle and get a guaranteed source of fresh eggs for breakfast, people have fallen in love with them.

“Chickens are really the new third pet out there,” Tractor Supply CEO Hal Lawton told CNBC on April 25. “The vast majority of our customer base partake in the category and they think of them as pets—they name them, take care of them that way, and it’s been a great new source of growth for us over the last five years or so.”

Among the company’s 34 million customers who are involved in its loyalty program, one in five owns chickens, he added.

Chicks themselves cost $3 or $4 apiece—but once a customer starts to build a flock, they need chicken coops, heaters, feeders, and waterers. The average flock size for customers is 14 birds, though nearly 30% of the company’s customers who raise chickens have 20 birds or more.

“In America, the new companion animal is the chicken,” CFO Kurt Barton said in a statement to Fortune.

In 2023, the company sold 11 million chicks, which was more than double the number sold 10 years ago. In 2022, the company launched a brand, Impeckables, to cater to poultry hobbyists. Branded items include chicken toys like a xylophone, tambourine, and fruity treats mixed with mealworms—and they’ve been “all the rage this year,” said Nicole Logan, senior vice president of general merchandising at Tractor Supply.

The company has also expanded its “chick days” events. What used to be a six-week project with live birds in the store for families to take in on a Saturday outing is now an eight-month event with clusters of fluffy baby chicks on display in stores under heat lamps with feed and water. The company is aiming to be a one-stop shop for anyone who wants to bring chickens home and set up a backyard flock.

A 2024 study of attitudes toward chickens found that 13% of U.S. households now own a collective 85 million backyard chickens, with an average of five per owner. A survey of 2,000 chicken carers as part of the study found that nearly 90% were women. Among the 20% who reported that they cared for chickens with health or other issues, such as special needs or disabilities, flock owners said they had used chicken wheelchairs, walking frames, or a hammock to support birds with broken backs. Some 82% of owners said they arrange for a chicken-sitter when they go away for a weekend, and 12% said they let their chickens come in the house whenever they want to.

That, however, introduces one of the only drawbacks of chickens—their bathroom habits. “If you’re sitting on the couch watching TV with your chickens, you’re definitely going to get pooped on,” said Cristante. She runs an Etsy shop, Chickenwear by Sue, where she sells colorful hand-sewn chicken diapers and takes custom orders. She’s shipped fashionable chicken apparel to clients in Chicago, Los Angeles, New York City, and nearly every state in the U.S., she said. For one customer in England who included a pet chicken in her wedding party, Cristante made a dress with a white satin harness, small veil, and tiny pearls, with a burgundy bow on the back to match the groomsmen. “It was a very interesting project,” she said. In New York City, a client asked for a Halloween costume, and Cristante sent vampire outfits with detachable capes and bat wings.

“Chickens—if you’ve never been around them and don’t know—have their own personalities, and some of them are quite affectionate and smart,” said Cristante. She described one popular breed of fluffy chickens known as silkies “like huge cotton balls. They’re very docile and easy to take care of and, honestly, they make very good house pets.”

Trish Sie, 53, a film director in the Los Feliz neighborhood of Los Angeles, started with half a dozen chicks and a coop from Williams-Sonoma. The flock grew after the chickens “exceeded all expectations for how fun they are to keep as pets,” she said. “They all have different temperaments and personalities. They learn their names and they’ll name you.” Sie, who directed films such as Pitch Perfect 3 and Players, also makes video content with her chickens, including dances and music videos.

“I’m so bonded to our dogs, and they really are like man’s best friend for a reason because they love people,” said Sie. “But with chickens, you have to earn their trust because you’re a big thing that can eat them.” Currently, her family has 11 chickens plus a rooster named Brian.

Sie first thought she was imagining things when she realized that the chickens all made the same sound when they saw her. But after looking into it, she learned that chickens have names for a number of things in their lives. After being gone for three months on a film set, she came home late at night after the chickens had already put themselves to bed. Just before midnight, she crept over to the coop to see them in the roost and whispered, “Hi chickens.” Three woke up and sleepily clucked the sound that is their “chicken name” for Sie.

Sie’s favorite, Ruby, sadly passed away last summer. The bird had a long life with Sie. Once, after suffering a prolapsed cloaca, a common issue for female birds, Ruby let Sie hold her for several hours while her husband gently “reset” the organ with his hands. Ruby lived another three years after that. “That’s the stuff they’ll let you do when they just trust you,” she said. A jeweler friend is recreating Ruby’s foot in sterling silver inlaid with onyx stones; Sie plans to wear the piece around her neck to honor Ruby.

According to Tractor Supply’s Lawton, part of what’s undergirding the chicken boom is the overall lack of affordability for Millennials and Gen Zers in urban areas. One of the only areas those demographic cohorts can afford to buy homes is in exurban, suburban and rural parts of the country. The U.S. Department of Agriculture’s economic research service found that migration to rural areas kicked up by a factor of 45 between 2020 and 2022, compared to pre-pandemic.

“It is our view that the sense of community found in our markets, perhaps more importantly, the ability to secure a piece of property at a reasonable price, has ensured that rural migration trend is one that is here to stay for the time being,” said Lawton during the company’s earnings call last week.

Once there, the Millennial and Gen Z generations seek to live a cleaner life, gardening fruits and vegetables and keeping chickens, said Logan. The poultry category is a gateway to a more sustainable living lifestyle, she said. Plus, that demographic is willing to spend more for organic ingredients. A decade ago, organic chicken feed made up 1% of the company’s sales in the poultry feed space; now it’s over 10%, she added.

“I wake up every day thinking, ‘How do I get more people interested in this?’” said Logan.