It takes a while for John Leguizamo to get into sloth.

“I’ve got to walk around the house a lot the day before, working on the lisp so that it’s not too much, that it’s just right,” he says, demonstrating.

Sloths have lisps? The ancient ground sloths did, as Leguizamo interprets Sid the Sloth in the “Ice Age” animated films – including the third installment, “Ice Age: Dawn of the Dinosaurs,” opening in theaters today.

“Sid’s a vulnerable character, with a higher-pitched voice than you’d think,” he explains. “So I have to tighten up, get the voice up there so that he doesn’t sound like a sloth who’s been out partying all night.

“I don’t get to work with Ray (Romano) or Denis (Leary, his vocal co-stars in the films). It’s just me and a script, not even a picture of what the scene will look like. You create the whole emotion of the character and what he has to do in this scene with your imagination.”

Leguizamo, who turns 45 at the end of July, marvels at how producers keep finding funny things for Sid the Sloth to do.

“They’ve been sending Sid off on separate little adventures these last two movies. I start out with the group, get rejected, go off on my own and get into trouble. In this one, I come across three dinosaur eggs and I get to represent single moms all over the world!”

The “Ice Age” movies are critic-proof, but Leguizamo still figured out a way to win over his toughest audience – his son and daughter, ages 8 and 9.

“They loved it to death, man. But you know, they’re a little biased. They’re in it. My son was ‘Beaver Boy.’ And my daughter was the aardvark.”

The birthday bunch

Actress Olivia de Havilland is 93. Actor Jamie Farr is 75. Actress Karen Black is 70. Actress Genevieve Bujold is 67. Singer Deborah Harry (Blondie) is 64. Actor Dan Aykroyd is 57. Actor Andre Braugher (“Homicide”) is 47. Actress Pamela Anderson is 42. Rapper Missy Elliott is 38. Actress Liv Tyler is 32. Actress Hilarie Burton (“One Tree Hill”) is 27.