Early in her existence, Hazel the Handful clarified the rules.

She would be glad to sleep the way babies are supposed to. But she expected to be in a moving vehicle at all times.

"I literally would drive around in circles," says her mom Stacy Traub. "My neighbors thought I was a stalker."

It was a strange time but a funny one. That's important to Traub, who writes comedies.

Tonight, her "Notes From the Underbelly" returns to ABC. In an early episode, a mom nudges her baby to sleep via tour-bus rides.

"Underbelly" started with a book of the same title, by Risa Green. Someone sent it to Kim and Eric Tannenbaum, TV producers with a preschool son.

"It's funny; it's specific," Kim says of the book. "It's unique. It captured a lot of things in a real and honest way that I hadn't seen on television."

They asked Traub to create a series. The timing was perfect.

Pregnancy and childbirth had brought Traub all the expected joys, plus unexpected quirks. "I thought, 'Why didn't anyone warn me?' "

Now Hazel was 4 months old and sometimes sleeping, and Traub had emerged from the dark side. "I was definitely on the other side of it, but I remembered it vividly."

Here was a chance to partly turn her life into a TV show.

Early on, for instance, Traub hadn't told anyone she was pregnant. One show was ending, she would be looking for a job soon and didn't want to complicate job interviews.

So at a farewell party, she pretended to still be drinking. "I was literally throwing tequila shots into a planter when no one was looking."

That became part of the first episode. "Underbelly" borrows liberally from the lives of Traub, the Tannenbaums and the show's writers.

Jennifer Westfeldt, a favorite of independent-film fans, plays the central character, still pregnant as the new season starts. Casting the father-to-be took longer, Traub says. "We were at a desperation point."

She was watching Anton Chekov's "The Cherry Orchard," she says, when she was impressed with the comic timing of Peter Cambor. "I didn't have great seats, but I could tell he was cute."

Cambor was still wearing a Chekovian mustache and sideburns when he auditioned. He got the job.

Michael Weaver plays his friend, Danny; Rachael Harris plays Westfeldt's friend Cooper, a divorce lawyer who is fiercely unattached.

"I'm living this complete opposite life ... being promiscuous," Harris says.

Another contrast comes from Julie and Eric (Melanie Paxson and Sunkrish Bala), who have a new baby and a relentlessly positive attitude. "Even when things go wrong, they don't seem to realize it," Bala says.

There's a great sense of detail here, he says. That includes the babies who alternate in the show.

"They found a set of triplets who are half-Indian and half-white ... and for the second season, they found another, similar set of triplets," he says.

This is new turf for most of the actors, who quickly studied parenthood. "I didn't know people go into it with so much preparation," Bala says.

He's accustomed to new turf. Bala was born in India, moved to the U.S. at 5 months, then spent some time in India and Singapore. "It gives you an outside perspective," he says.

Now he plays a first-time parent during a time when everyone feels like an outsider.

There are plenty of episodes. "Underbelly" has five left from its trial run last spring and got a quick start in the fall. As the TV writer strike began, it knew it could do 15 weeks without reruns.

And new stories emerge.

Hazel is 3, still high-energy, still dubbed "the Handful" by her parents. Now she has a 5-month-old brother. Their mom expects to have plenty of new story ideas.