Nesting birds pop in and out of the eaves of the springhouse, and butterflies and bees fly from flower to flower in the somewhat wild-looking gardens surrounding a white clapboard farmhouse in Springdale, northeast of Pittsburgh.

The scene looks decidedly out of place on Marion Avenue, an ordinary suburban street lined with ordinary bungalows and ranchers surrounded by an ordinary suburban landscape -- closely cropped lawns, heavily sculpted shrubbery and ho-hum plantings of marigolds and geraniums.

But it all makes perfect sense when you realize you're looking at the birthplace and childhood home of ecologist and author Rachel Carson.

Carson, credited with launching the modern environmental movement, would be pleased with the appearance of her homestead and its gardens, filled with plants, bushes and flowers native to western Pennsylvania.

The natural gardens teach visitors about the interconnectivity of life and educate gardeners about the importance of using native plants. All are maintained without pesticides or synthetic fertilizers, whose dangers motivated Carson to write her 1962 book "Silent Spring."

The book, a literary bombshell, detailed extensive and alarming research Carson had collected about the effects of chemical pesticides on wildlife.

She visited Hawk Mountain and cited data from migration counts there that showed a decreasing trend in the number of young bald eagles.

"Synthetic pesticides have been recovered from most of the major river systems and even from streams of groundwater flowing unseen through the earth. Residues of these chemicals linger in soil to which they may have been applied a dozen years before. ... They have been found in fish in remote mountain lakes, in earthworms burrowing in soil and in the eggs of birds -- and in man himself," she wrote.

Carson was posthumously awarded the Presidential Medal of Freedom (the highest honor the United States gives to civilians). She was named to Time's "100 People of the Century" in 1999 and was No. 1 on the list of "People Who've Done the Most to Save the Planet," created by the United Kingdom's Environment Agency.

In addition to articles written when she worked for the Bureau of Fisheries, she penned "Under the Sea Wind," "The Sea Around Us," "The Edge of the Sea" and "The Sense of Wonder" (published after her death).

Nevertheless, a surprising number of the homestead's visitors still ask, "So who was Rachel Carson?" according to Fiona Fisher. She leads tours of the house, which is open by appointment only.

What is that legacy? The restoration of species including bald eagles and peregrine falcons. A ban on the use of DDT in the United States and the regulation of other chemical pesticides. The Clean Air Act, the Clean Water Act and the Environmental Protection Agency (all created within the decade after "Silent Spring" was printed). And the beginning of the environmental movement in the United States and abroad.

It all began here, on a quiet hillside above the Allegheny River, about 15 miles northeast of Pittsburgh. Carson, the youngest of three children, was schooled by her mother to appreciate nature and explore the family's property, which once included 65 acres of fields, woods and an orchard.

"Because Carson was so important and famous, children expect to hear that she was rich and lived in a grand home," says Fisher.

"Instead, they look around and see her very humble beginnings. The home had no indoor plumbing. The water the family needed was carried from the springhouse. Each room was heated by a small fireplace. And Rachel, her brother and sister probably shared one room."

Rooms are furnished in the style of the times, rather than with the family's actual belongings. But while standing in Rachel's bedroom, it's possible to imagine her peering out her window to plan her next adventure.

At 14, she wrote an account of one exploration called "My Favorite Recreation." Published in a children's magazine, Carson describes "going birds'-nesting -- in the most approved fashion" (with a canteen and lunch, plus a notebook and camera).

She writes about the trail, which "turned aside into deeper woodland and wound up a gently sloping hill, carpeted with fragrant pine needles. ... It was the sort of place that awes you by its majestic silence, interrupted only by the rustling breeze and the distant tinkle of water."

In her ramblings that day, she came upon the nest of the Maryland yellow-throat, "containing four jewel-like eggs" and "came close enough to snap a picture." She also found a bobwhite's tightly packed nest of eggs, the "framework of sticks the cuckoo calls a nest, and the lichen-covered home of the hummingbird."

The home's plantings in the Welcome Meadow, the Springhouse Garden and the Homestead Border convey Carson's messages about the relationships between plants and the earth, plants and other plants and plants and animals to young children, students and adults. As Carson observed, "Nothing in nature exists alone."

The Wild Creatures Nature Trail, which begins behind the house, is an easy 15-minute walk. It encourages parents and children to explore and experience the outdoors together and to help children develop a love of the outdoors.

As walkers complete the trail and pass through the homestead's back yard, they may spot an abandoned bird's nest perched on an old wooden bench. Was it left there by accident? One wonders.