BioFables: Book 3, Series 1Ages 10-adultWhat's cooler than a geodesic tent? Igloos (They have the same basic overall shape). Also cool: learning that the straight lines of their family tent's triangles and an igloo's square-ish blocks of snow are arranged to make surfaces that are rounded.What's hot? Climbing sand dunes in summer. Mallory's seven-year-old twin sister, Melody, enjoys the heat. Mallory? Not so much. He and his Dad head back down the dune while his Mom and sister continue their upward trek. In the shade of a small bush, Mallory discovers more than cooler sand as he settles into a little trench that his dog Rufus helped to dig.When Mallory and his father visit the local Indiana Dunes police station to turn in their find, they learn why some dunes are called "living." The police sergeant explains. If you bury something near the bottom of a sand dune and it stays buried for many years, chances are you won't find it in the same location. That's because grains of sand are blown in the direction of air currents; over time, the sand dune shifts, making it look as though it moved by itself (and therefore "living"). Over the next several months, the family learns the history behind Mallory's accidental discovery, but for now, the police sergeant thanks the father and son with coupons for free ice cream at the local shop that the whole family can enjoy.Melody is mildly interested in the living dunes explanation, but she's even more curious about how the dunes got there in the first place. Flat sandy beaches are one thing, but large hills of sand? Glaciers and rocks, her Mom guesses, and suggests they'll find out more at a program hosted by the park rangers.Mallory suggests that they split up after lunch; he and his Dad could then explore the Big Blowout and tree graveyard while his sister and Mom could visit wherever they want. Melody thinks that's a great idea, since she's much more interested in experiencing the quaking bog and seeing insect-eating plants.Walking on Pinhook Bog's springy boardwalk is great fun for Melody. She and her Mom learn that extremophile bacteria are able to live in the bog, even though there's no oxygen. She also gets to investigate the hairy plants that eat bugs because the ground doesn't have enough nutrients for them to survive. A hawk and a squirrel demonstrate the food chain in action; Melody holds and pets a scared little squirrel that also witnessed the action. Wild squirrels allow everyone to hold and pet them, right?Meanwhile, Mallory, his Dad and Rufus come to a big hollowed-out area where blowing winds scooped out the sand, making what looks like a giant-size soup bowl. Mallory discovers that you can't stop a dog running in sand by stepping on its leash. With a little help from his Dad, Mallory figures out how wind, sand and changing weather conditions create tree graveyards. At the Nature Center program, the family learns about the park's preservation and restoration activities; Rufus promptly falls asleep. A visitor rudely interrupts the rangers' talk about the area's "singing sands." This confrontation gives Mallory and Melody a practical lesson in how to address rudeness politely, yet effectively. The next day, Melody and her Mom ignore their aching leg muscles as they test out the noisy sand that squeaks when you walk on it. Everyone agrees that doggie paws aren't nearly as musical as human feet. Everyone agrees, though, that doggie paws are better at destroy sand castles.Inspiring their children's creative juices to flow, the twins' Dad demonstrates how to draw dunes with four colored pencils in one hand, and their Mom writes a poem about their visit. Mallory was inspired to bring home a rather large souvenir of their trip. His Dad telephones the sergeant to talk about the dune discovery and his son's acquisition from the park. How much trouble is Mallory in? Find out in BioFables, Book 4.BioFables' next title: "Palisades Escapades."