Los Angeles ? The set of “Two Brothers” was like a reverse zoo: The tigers roamed free while the humans paced back and forth in cages.

The sweet-natured story from director Jean-Jacques Annaud, who made the 1988 wildlife drama “The Bear,” chronicles two tiger siblings who are reunited in adulthood after being snatched into the human world.

But tigers can be more fickle than even the most temperamental Hollywood A-lister — these feline actors will LITERALLY chew up the crew if provoked. The only way to let the adult tigers feel relaxed enough to showcase natural emotions was to cage their prime distraction: humans.

“We went under the principle that tigers are extremely dangerous predators, that they are in some ways unpredictable — especially when they look so tame and so nice,” Annaud told The Associated Press. “We never forgot that tigers can be trained but never tamed.”

The movie also features “Memento” star Guy Pearce as a hunter and treasure collector who learns from the creatures that humans can be more deadly than the animals they fear.

When Pearce arrived in Cambodia, he was taken to the set to observe a tiger rehearsal. “The first thing they did when they got me out there was stick me in a cage. I found the whole thing deeply ironic,” he said.

Although dozens of cats played the two leads for stunts, long shots and stand-ins, the same two animals were used, as kittens and then nine months later as adults, for the closeups and intimate shots.

They were Kumal and Sangha, named after their characters in the movie. They now reside together at a naturalistic zoo in the Puy Du Fou park in France.

“They have at least 50 different expressions,” Annaud said. “What I didn’t realize when I started this movie is that tigers are creatures that can show so many nuances of emotion on their faces.”

Antiquities hunter Aidan McRory, played by Guy Pearce, removes one of a set of twin tiger cubs from a looted temple in this scene from the adventure drama Two

The tigers were less of a danger when young, about 4 months old. They could interact safely with the human actors in most scenes, and Pearce even lets one nibble harmlessly on his hand in one sequence.

“They’re very much the same as a domestic cat. They’re moody, they want to play, they want contact, and if they get fed up with something they’ll swat you with their claw and let you know,” Pearce said. “I definitely got a nip every now and then … and one of them bit me on the shoulder, gave me a scratch. It kind of hurt, but I thought for the rest of my life I can say, ‘I was bitten by a tiger.’ It didn’t scar, which I was a bit sad about.”

The adult tigers were the real danger — the movie’s theme is that these creatures should not be hunted out of fear, but should be avoided out of respect.

The filmmakers cordoned off several acres of Cambodian jungle with fence and netting to keep the trained tigers from wandering too far into the wilderness. Then about five or six human cages, which could contain around 100 people, were set up around three to four remote-controlled cameras.

Once all the people were safely locked away, the tigers were set loose. A few trainers would try to guide their movements according to the script, but Annaud said the animals preferred to improvise.

“Tigers are very much like when you shoot something with children. You have to let them reinvent the scene by themselves by organizing the set, the props, even the light,” the director said. “You have to let the camera run.”