SANTA CRUZ, Calif. Every mother with a new baby has to figure out what to do when the baby wakes up at night and cries. Alicia Zenteno knows that crying is the way a baby communicates.

“It’s OK,” said Zenteno, 29, whose daughter Sofia is 3 months old.

“She’s trying to tell me something.”

She knows how to soothe her baby and “not be anxious and desperate.”

It’s not something she learned when her older daughter, Camila, was born more than three years ago.

Instead, she learned the secrets of baby behavior from Jane Heinig, executive director of the University of California-Davis Human Lactation Center, who visited Santa Cruz and Watsonville, Calif., last month.

While interviewing mothers participating in the federally funded Women Infants Children nutrition program, Heinig discovered many switched from breast feeding to formula and cereal, believing their babies awoke at night and cried because they didn’t get enough milk.

She teamed up with the WIC program to provide handouts to parents explaining how often infants wake at night three to four times per night in the first eight weeks and why they cry.

It could be the baby needs a diaper change or a break from activity rather than another feeding. A baby that frowns may be a sign of too much interaction or too much noise.

Her groundbreaking three-year study found that when mothers got information about baby behavior, more breast fed their infants exclusively for the first four months, and the percentage of overweight babies dropped.

A year and a half ago, Heinig started a “Secrets of Baby Behavior” blog, short 500-word posts illustrated with baby photos. It has grown from 40 readers to more than 36,000.

“So many parents needed this information,” she said, recalling how a father soothing his baby at the Phoenix airport told her he knew what to do because he read a blog about it from the University of California-Davis.

Now, Heinig is spreading the word statewide.

Her Santa Cruz County, Calif., visit was organized by a coalition of health care organizations including Dominican Hospital and Sutter Maternity & Surgery Center and Community Bridges, which runs the Women Infants Children program locally.

“This is a great opportunity for our staff,” said Kimlin McDaniel Keith, coordinator of Dominican’s baby-friendly hospital initiative.

Parents of a newborn may be short on sleep but that’s normal.

“A 2-week-old sleeping through the night is not normal,” said Robbie Gonzalez-Dow, the regional breastfeeding liaison at Community Bridges, after hearing about babies being given Benadryl at night.

Deutron Kebebew, who heads the PAPAS fatherhood project in Watsonville, Calif., said information about normal baby behavior would be useful for dads, too.

To raise a child, he said, “it takes two.”