There’s an old saying in Hollywood: Never work with children or animals, as both can outshine the stars.

“Actually, making this movie was the opposite – I got to work with both kids and animals,” shares Ben Stiller regarding his new holiday film, “Nutcrackers” (premiering Friday on Hulu).

Before Stiller, an experienced actor (“Meet the Fockers”), director (“Tropic Thunder”), and producer (“Severance”), can elaborate, one of his young co-stars, 11-year-old Ulysses Janson, interrupts.

“Yeah, they should really say, ‘Never work with adults,'” declares Janson, who prefers to be called Uli.

Stiller responds with a classic wide-eyed Ben Stiller look, remarking, “I think you might be onto something, kid.”

For the next 20 minutes, the conversation flows effortlessly, filled with light-hearted teasing between the 58-year-old actor and two of his young co-stars: 13-year-old Homer Janson and the 8-year-old twins, Arlo and Atlas.

This chemistry shines in “Nutcrackers,” a feel-good movie directed by David Gordon Green (known for the 2018 “Halloween” reboot). The story features career-driven Michael (Stiller) as he looks after his lively and recently orphaned nephews while they wait for news about their foster placements.

The Janson brothers’ real-life adventures inspired Hulu’s ‘Nutcrackers’

“Nutcrackers” stands out because Green discovered the four Janson brothers while visiting an old college friend on her family farm near Wilmington, Ohio. Spending time with her unique and talented children sparked an idea for a film, complete with actors and a location.

Stiller recalls: “David called me up and said, ‘Hey, I’ve got this holiday movie concept featuring these boys living on a farm, none of whom have acted before. We’re going to use 35-mm cameras and get rolling in eight weeks. Are you in?'”

Initially, Stiller expressed doubt, wondering if it was going to be a parody of holiday movies. “But it wasn’t,” he admits.

Stiller was intrigued, partly due to his love for classic holiday films.

“I never thought, ‘I need to do a holiday movie,’ but I do enjoy them, from those Rankin/Bass animations like ‘Rudolph the Red-Nosed Reindeer’ to ‘It’s a Wonderful Life,’ ‘Planes, Trains & Automobiles,’ and ‘Polar Express’ – all films that really get you in the holiday mood,” he explains. “I also appreciated how organic this felt – it didn’t come across as a big studio production.”

The Janson brothers transitioned from inexperienced actors to skilled performers, according to Ben Stiller

The Janson brothers took to acting naturally, Stiller notes, especially since their own family farm served as the film’s setting.

“These kids live in that house you see in the film, so even when we’d yell ‘cut,’ the cats, guinea pigs, dogs, and goats were still wandering around casually,” Stiller says. “Sometimes, you couldn’t even tell if the cameras were still rolling.”

Homer Janson recalls that he and his brothers worried about having to clean their home once filming started. To their surprise, they learned that their messy homestead was actually perfect. “It was meant to look like four boys have been living alone, and we made sure it did,” he jokes.

The boys quickly became familiar with the filmmaking process, enjoying the perks (“The free breakfast burritos every morning were a definite highlight,” Uli Janson enthusiastically shares) and the terminology.

“At first, when we said ‘Step on your mark,’ they would ask, ‘What’s a mark?'” says Stiller. “By the end, they were discussing terms like, ‘That’s a 30-mm lens, and he’s going to do coverage for an over-the-shoulder shot.’

What lies ahead for the ballet-dancing Janson brothers? A performance of ‘Nutcracker’

Do the Janson brothers have more acting planned now that they’ve excelled? With their ballet skills featured in “Nutcrackers,” the answer might be yes.

“We’re currently training for a performance of the actual ‘Nutcracker,’ which will be held at the same local theater you see in the film,” shares Homer Janson.

Leaning in, Stiller quips, “But I’m their manager now. I have ownership of their life rights; their parents sold them to me. You all are fine with that, right?”

Home and Uli share a grin, feeling like they’ve known Stiller for ages. What’s the best part of collaborating with him?

“Ben is incredibly nice, just so amazing” Uli praises. Stiller responds with a deadpan, “Keep it coming, please.”

So, what’s their top pick for a Ben Stiller film?

“Well, Homer has watched ‘Alex the Lion’ maybe 15 times,” Uli mentions, but Homer quickly clarifies, “You mean ‘Madagascar.’ ”

Stiller lent his voice to the lion in that popular animated movie. He reacts swiftly, “True, but it should have been titled ‘Alex the Lion,’ without a doubt. Good catch, Uli.”

For Homer, Stiller’s top films are “Tropic Thunder” and “Zoolander,” but he’ll soon add another title to that list after working with the star.

“The entire experience was really great, working alongside Ben,” he reflects.

While Stiller might appreciate the compliment, he can’t help slipping in a comedic remark.

“Sure, initially it was nice,” he replies with a shrug. “But later on, let’s be honest, things got tense. We stopped communicating, with comments like, ‘Hey, why does Uli have a bigger trailer than I do?’ ”

Stiller glares at his long-haired co-star and jokes, “Uli, I think fame has gotten to your head.”

But Uli is too busy laughing to respond.