All across the country, children and adults are discovering that the real fun at a zoo begins after hours and can last all night long.
Saturday Early Show national correspondent Gretchen Carlson followed the Thompson family as they discovered the fun that continues into the next morning when campers awaken to the calls of the wild and head off on a scavenger hunt to find a missing lion cub.
Each year, the Washington, D.C., National Zoo holds 60 "Snore and Roar" adventures. Many other zoos across the country also hold sleepovers year-round.
From Los Angeles to St. Louis, zoos across the country are extending their hours. A night at the zoo can be filled with noises of screeches, snorts, crackle or roars - a change from the honks and sirens of the city.
The Thompson family took part in one recent overnight stay. When the National Zoo closed, the Thompsons stayed put for a sleepover, right in the middle of the wild kingdom.
Cathi Thompson said the "Snore and Roar" program sounded like the perfect family adventure.
"This is a very unique experience, I mean nobody they know has slept out at the zoo. To do this is very exciting," she said about her kids. "But, also I think, they're going to learn something about cheetahs tonight from the back, behind-the-scenes tour. I think that will be good for them."
It's not the cheapest adventure. Prices range from $40 to $85 per person, but that buys a close-up and personal look at all kinds of zoo life.
If sleeping outdoors with wildlife isn't your calling, you can tuck in the turtles at an aquarium. At the South Carolina Aquarium, after a flashlight scavenger hunt, campers get to pick where they bunk down for the night.
At most aquariums and zoos, all you need is a pillow and a sleeping bag. The park takes care of the rest. At the Los Angeles "Sundown Safari," the zoo even supplies special equipment for a night hike.
And if you don't see any animals during the Fort Worth, Texas, sleepover, don't worry. After dawn, campers go on a morning tour.
All of this exploring isn't just for kids. The San Diego Zoo's "Extreme Africa Sleepover" is an adult-only, "Survivor" type sleepover. It features an animal touching game, a bamboo stretcher race and an eating challenge.
The San Diego Zoo was one of the first parks to offer the overnight experience in the mid-1980s. The popularity of these family sleepovers has grown during the last few years. Some parks will let you rent the entire zoo for an overnight birthday party - for a fee of around $4,000.
All the money in the world won't guarantee that the critters will cooperate. But the Thompson didn't find it hard to see the cheetahs on this night. After five hours of learning about cheetahs, trekking past the elephants and giraffe house, stopping to check out the camels and hiking down Beaver Valley Trail, only one word could describe our intrepid campers - tired.
And the best part of seeing the zoo after dark?
"It was mostly just us," said Brett, the son.
"But the animals seems a little more relaxed, like what are you doing here," said Cathi.
"Yea, like what are you doing here at this time of the night," said Dani, the daughter.
After all the exploring, it's finally time to turn in.
Bedtime rules exist here as well. Gum and radios must stay home. Voices should be kept low and flashlights must be turned off at 11 p.m. But don't count on getting much rest.
"We were told that the gibbons were going to be waking us up at six and then the lions will be roaring around seven, so I think it's going to be a short night sleep, " said Cathi.
"Yeah, not too many kids will get woken up in their life by a lion roaring. So I think it will be a pretty neat experience tomorrow morning to hear that," said Randi, the father.