In an interview in Entertainment Weekly's Oct. 30 issue, the 42-year-old actor says he amused himself and his colleagues by yanking up his pants to give himself a wedgie sticking out his rear and waddling about like a duck. "Throughout the movie, I'd walk around like this," he says.
"You've gotta find things to make you laugh during the shoot," he adds. "Cate (Blanchett) called it the Hungry Bum."
He explains: "When your bum's so hungry it's trying to eat your pants."
His character's story line in "Babel," in theaters Nov. 10, is not as amusing. He and Blanchett play husband and wife in the multinational drama that follows several families linked by a tragedy in the African desert.
Pitt felt a personal connection to the movie's one-world message — he is, after all, the adoptive father to girlfriend Angelina Jolie's children, Maddox, 5, from Cambodia, and Zahara, 1, from Ethiopia. The couple have a daughter, Shiloh Nouvel, who was born in Namibia in May.
"Our kids come from different parts of the world, and it's the perfect example of, if we didn't have these perceived differences we wouldn't be defined by geography," he said.
"What I liked most (about the script) was this idea that we're all the same, and it's our lack of understanding and lack of communication that gets in the way."