Imaginators Jerry G. White and Eric Little perform "Tulie's Roots" at the children's museum. Jamie Gumbrecht/AJC

Most times, Imagine It! The Children’s Museum of Atlanta pulses with the force of the sippy-cup set.

But for 20 minutes about five times a day, most everybody slows down, finds a comfy spot on the carpet and catches a show.

It’s the first experience with live theater for many, and from the moment the Imaginators open their mouths, kids are mesmerized. Children’s museums often partner with youth theaters, but few have a steady group of professional actors who are their own exhibition — writing musicals, choreographing dances and performing them on the museum floor with the exhibitions as their backdrops. (Check out photos of an Imaginator performance of “Tulie’s Roots.”)

“It’s guerrilla theater; it’s street theater,” says Pamela Duncan, the museum’s program manager. Actors are the bridge between objects on display and how children learn, she says. They also do outreach programs outside the museum, offering art and education where the exhibits can’t.

When Duncan was hired shortly after the museum opened six years ago, she had a long stage background, no museum experience and an order to build a theater troupe. The Imaginators are now a 12-person force that writes a new show for each traveling exhibition and leads an activity several times a day. After the museum closes, they go on to Atlanta’s more grown-up stages and film studios.

But the actors have become experts on entertaining children. Since their first show — a script that came with the “Arthur’s World” exhibition in 2005 — they’ve written their own material, growing as they understood what works for the waist-high crowd. A basic guide: giggles are good; pint-sized mutiny is bad.

“Parents say, ‘I can’t believe my child sat that long,’” said full-time Imaginator Jerry G. White, 52, who worked with the museum even before it had opened.

Here’s what the Imaginators have learned about capturing kids’ imaginations.

Kids like to hear from their own.
To match the “Exploring Trees Inside and Out” exhibition that continues through Sept. 13, Imaginators created a musical about Tulie, a Tulip Poplar who talks to a little boy. Pat Hall is played by 30-year-old actor Eric Little, in cuffed jeans and Converse high tops. When Pat’s dad shoos him away from video games, the 8-year-old whines, argues, delays — then obeys his dad and heads outdoors.

Pat, a character in "Tulie's Roots," sneaks up on another. Jamie Gumbrecht/AJC

Kids love to be scared.
Easiest laugh in the show: when one character sneaks up on another. The louder the yelp, the better. “They like the sound, the movement, the reaction,” White says.

Kids are smarter than you think.
Words will go over kids’ heads, but Imaginators don’t like to use silly voices, sound effects and made-up blabbering to entertain. “You take them to this fantasy truthfully,” Little says.

Always, always use music.
The Imaginators write not just a play, but a musical. (White’s father, a jazz musician, usually writes and records the music for them.) Two upbeat songs per show will hypnotize an antsy audience of tots. Repeat the lyrics a few times and they’ll sing along. “He kept saying ‘Music, mommy, music!’” Lauren Howell of Braselton said of her 2-year-old son, Liam. “He could barely contain his excitement.”

Be in there with them.
Imaginators often sit among the audience and pull them into the show. If a rogue child toddles up on “stage,” he’ll be incorporated into the play until a parent fetches him. It might be the biggest difference between theater for adults and theater for kids, Little says: “With the kids, we break the fourth wall every day. The show is always in the present.”

Keep parents happy.
There’s no adult humor, but some jokes are more for parents than kids. During a baseball scene in “Tulie’s Roots,” the actors repeat an old Skip Caray call, something most kindergartners won’t catch. And at the end of the show, young Pat admits, however reluctantly, that sometimes parents are right to send their kids outside.

Want to go? Imagine It! The Children’s Museum of Atlanta is at 275 Centennial Olympic Park Drive N.W. in Atlanta. Admission is free for children younger than 2 and $12.50 for visitors age 2 and older. For more information, call 404-659-5437 or visit www.childrensmuseumatlanta.org.