My husband stares into the pitcher plant. Two tiny eyes peer back. "There's a frog in here," he announces, immediately getting our children's attention. Worry ripples through our little group.

Could this red carnivorous plant actually eat a peeper?

Evan, our 4-year-old, gently pokes the plant with a stick. The frog hops out and the plant is left to catch its normal diet of midges and mosquitoes.

This life-and-death drama took place early this month at the Suitland Bog off Suitland Parkway. Bought by Maryland-National Capital Park and Planning Commission in 1976, the bog, covering about 60 acres in Suitland, features a half-mile boardwalk and a half-mile wooded trail. We were on the free, once-a-month tour, but the trail and boardwalk are open daily from dawn to dusk.

"We like to encourage people to come and see it, instead of closing it off," says Chris Garrett, the park ranger and our guide. However, to limit access and protect the rare plants, the parking lot next to the trail is unlocked only during these Saturday tours.

The bog, described by botanical enthusiasts in 1901, has survived years of neglect and abuse, including a period in the 1960s and '70s when the now-forested area around it was a gravel pit. After walking past a few scrub pines, Garrett points to an outcropping of stones. "When it was a gravel pit, the whole area looked like this," he says.

In the thin layer of topsoil, pines were the first trees to grow after the pit was no longer in use. Deeper into the woods, broad-leafed trees, including sweet gums, are taking over.

We stop near them, and Garrett points to signs that the cicadas are emerging. "Caps," he says. Several members of our seven-person group understand, because they were around in 1987 during the last cicada invasion.

I, however, am confused. "Caps?"

Caps are the little clumps of dirt that covered the cicadas' holes. As the bugs came out they pushed the caps away and climbed the trees. Scott, my 6-year-old, and Evan collect the caps and smush them back on the empty holes.

We admire a collection of pink lady slippers (an endangered native orchid), then walk through the open gate to the fenced-in bog. The boardwalk, only about four inches off the ground, relieves my worry that one of my children might accidentally step on an endangered plant. Garrett tells them, and the rest of us, that he is the only one allowed to step off the walk. They listen and run along the boards, enjoying the sound of their feet on the wood.

Nearby, water trickles from a spring. We've already passed several in the woods. "They come from an underground aquifer," Garrett says. The moving water means Suitland Bog is not a true bog. By definition, he says, a bog is a rain-fed wetland. "This is actually a fen," he says with a shrug. "The plants are the same."

Many plants have yet to bloom. Garrett points out buds on tall blueberry bushes and mountain laurel. We see two painted box turtles and a skittish rabbit, but the favorite spottings are the two species of carnivorous plants. The tiny sundew entices no-see-um-size insects to its sticky leaves. The bugs that are trapped give the sundew what it needs to grow.

Garrett explains that the pitcher plants, which are larger, attract bigger insects with bright red stripes on their dark green and red leaves. The bugs land on the leaves and then slide into the plant's bowl-like part below.

Unlike the frog, the bugs can't get out. "They're toast," Garrett said.

Or, from the plant's perspective, they're dinner.

Suitland Bog is located at Suitland Road and Suitland Parkway in Suitland. (From the Capital Beltway, take Exit 7A, Branch Avenue, toward Waldorf. Take Route 5 south. Make a left onto Allentown Road. Stay on Allentown Road through five lights. Turn left onto Suitland Road at the sixth light. Follow Suitland Road until it passes under Suitland Parkway. The entrance to the Suitland Bog is to the right.) For more information, visit www.pgparks.com/places/nature/suitland.html or call 301-627-7755. Free tours take place from 10 a.m. to noon on the first Saturday of each month, or by appointment.

Park Ranger Chris Garrett shows a painted box turtle to Evan Candey, front, his brother Scott and their father, Robert, and Karen Ihrig during one of the Saturday guided tours offered monthly at Suitland Bog. Covering about 60 acres of wetland, the park features a boardwalk and a wooded trail. Located off Suitland Parkway, Suitland Bog was purchased by the Maryland-National Park and Planning Commission in 1976 and is open daily. The bog has survived years of neglect and abuse, including a period when the area around it was a gravel pit. Clockwise, from left, a colony of eastern tent caterpillars has built a home; the sundew, a small carnivorous plant, has sticky leaves that trap tiny insects; and termites cover a piece of wood.