Not too long ago, my free-spirited daughter and another 3-year-old simply walked out of the front door of a neighbor's house toward a busy commercial district. After several minutes, disturbed by the uncommon quiet of their play, my neighbor checked and found that they were gone.

Together we searched her house and the surrounding area. But by that time our young wanderers had rounded a corner and were setting out on Connecticut Avenue, by all accounts at a very brisk pace.

Forty heart-stopping minutes later--after the neighborhood was mobilized in a search--the police had set up a "command center." When we had almost resigned ourselves to the very worst, our children were discovered in a pizza parlor trying to order french fries on credit.

Although lots of children may have a bit of Huck Finn in them, preschoolers are especially vulnerable adventurers. "Any child under 6 is automatically listed as a critical situation by Missing Persons," says Lt. Michael Fitzgerald of the District of Columbia Special Investigation Branch.

He recommends that parents put themselves in their child's place when looking for them. "A child is often acting out a fantasy. He simply decides that he wants something without perceiving danger.

Children are often missing inside the house, or it may be a domestic situation where the child goes to the father's or mother's house."

The worst mistake that parents can make, says Fitzgerald, is not calling the police soon enough. "Some people feel that they shouldn't call the police for either eight or 24 hours. They may believe in a fictitious rule that people aren't considered missing by the police for 24 hours."

Says Sgt. Steve Hargrove of the Montgomery County Youth Division: "Don't ever feel that you are bothering the police. A parent should wait no longer to report a missing child than it takes him to perceive that the child is lost."

Hargrove suggests that parents walk the neighborhood with their children, explain its safe parameters and inform neighbors of a child's boundaries.

To be prepared, have a current picture of your child. If the child is a chronic wanderer, an identification bracelet should be considered.

Hargrove also suggests that a family choose a code word to prevent strangers, for example, from approaching children with the excuse that their parents were called away on an emergency and he was instructed to pick them up.

"It's a little 'James Bond,' " Hargrove admits, "but it impresses on kids the seriousness of the problem."

"Childprint" is one of the most innovative--although controversial--programs available in some Washington-area jurisdictions. Since the Montgomery County Police Department began its program in the spring it has fingerprinted over 3,000 children. The prints are turned over immediately to parents; copies are not retained by the police department. Other jurisdictions and some schools are following suit.

The rather romantic picture of a young child wandering off bravely to experience the world can have a darker side, according to Dr. Joseph Noshpitz, a senior staff psychiatrist at Children's Hospital. "Children this age are not looking for adventure," he claims. "They are reacting in response to something."

Noshpitz suggests that a child may leave a stressful situation, trying to prove that he--not his parents--is in control. "The child may do the leaving rather than being left." Stresses on the child may include a break in established patterns, a change in or inadequate child care, family illness or even a new baby. Running away could be a child's bid for attention.

Spanking the wanderer, says Noshpitz, only increases the stress and may motivate the child to run away again.

"Talk to the child," recommends Noshpitz. "Find out what's wrong. Running away must result in more than a conference, but in a family's changed behavior."

Although Washington psychologist Shelley Rockwell agrees that a wandering child is testing both his and his parent's limits, she considers exploratory behavior as normal. A spanking, she says, may be appropriate so that a child is aware of his parents' anger and concern.

Meanwhile, of most concern to police are the children who are reported missing frequently, and in those rare cases they may recommend a social worker's intervention.