Each fall, the Lawrence Parks and Recreation Department encourages kids to get outdoors — and maybe get a little messy in the process. The goal behind these biweekly hikes is also the name of the annual program, cleverly titled “No Child Left Inside.”

Offered every other Wednesday between September and November, the kids-centric “Hiking Club,” as it’s alternatively called, leads a gaggle of young science enthusiasts and explorers on after-school adventures at Prairie Park Nature Center and nearby venues such as Clinton Lake and the Baker Wetlands Discovery Center.

The idea, says Prairie Park nature education supervisor Marty Birrell, is to get kids outside — and away from the TV, video game console and myriad screens — for about an hour and a half on those Wednesdays, when Lawrence’s public elementary schools (the program is aimed at kindergartners through sixth-graders) dismiss students for the day a little earlier.

“Kids are disconnected with the environment in a major kind of way because they’re spending all this time in school,” Birrell says. “Their time outside engaging in contact with the natural world has been seriously limited, unless these kids are in very, very rural environments. So, they’re not getting much opportunity to get outside and play in natural ways.”

When school ends for the day, Birrell says, plenty of kids head immediately into regimented activities like “soccer and ballet class,” which are perfectly healthy pursuits, she acknowledges, but not the kind of organic “free play” she believes integral to every child’s development.

And that’s assuming kids are getting outside at all. A global study earlier this year revealed that children worldwide spend less time outdoors per day than prison inmates. And, according to 2010 findings by the Keiser Family Foundation, they’re spending that time (seven and a half hours a day, for school-aged children) on electronic media.

That has left a lot of children, Birrell speculates, “afraid” or unfamiliar with the natural world around them.

In “No Child Left Inside” classes, Prairie Park naturalist Andrea Woody aims to offer an enriching educational experience that doesn’t simply mimic what students may already be learning at school. The adventures go beyond textbooks, Birrell says, to include hands-on activities such as fossil hunting, butterfly tagging and bird watching.

Kids, many of whom have become “No Child Left Inside” regulars, seem to enjoy the opportunity to learn more about nature in an immersive setting, says Birrell. The program is one of Prairie Park’s most popular, and still has two open spots (Wednesday and Nov. 2) this fall before closing for the season, she adds.

“We encourage observational skills and exploratory skills and really engaging themselves in a hands-on way with the environment,” Birrell says of the program’s perks.

There’s also the fitness benefit, she says, for kids who may not necessarily be interested in team sports but are still in need of physical activity after sitting in class all day.

“Everybody agrees that kids should be spending more time engaged in outdoor, physical activity,” Birrell says.

Outdoor playtime has been linked in studies with everything from reduction of ADHD symptoms in children, according to the American Journal of Public Health, to strengthened immune systems and lowered stress levels.

For more information on “No Child Left Inside” and other Prairie Park programming, visit www.lawrenceks.org or call the center at 832-7980.