WE WERE WONDERING what's been happening at the Zoo, so we strolled up Connecticut Avenue and turned in at the tall iron gates. The first thing we saw was people, lots of people: short, tall, fat and skinny ones, plain and beautiful, infants and elderly. We heard a lot of different languages, too -- German, French, Spanish, Chinese -- as well as children laughing and babies fussing.

It took a few minutes to get oriented, what with all the people, and to remember we were here to see the animals.

In one yard, a newborn giraffe was just struggling to its legs, shaded from the noonday heat by two adults. In another yard, an orangutan sat below an elaborate set of climbing bars, playing peekaboo with a scrap of burlap. On a byway, three large tortoises lumbered on the grass, and way down at the bottom of the zoo a white tiger was stretched out at the top of a terraced hill, twitching its ears and glaring imperiously.

We wondered what it's like to be an animal at the zoo. We'd heard that once a penguin got fed up with the summer heat and waddled across Connecticut Avenue and up a few blocks to a movie. We wondered if any of the other animals ever get impatient, or homesick. When we talked with some of the keepers, what we learned was not surprising -- no one really knows what animals think -- but it did give a more vivid sense of zoo life.

The following are the stories we uncovered. And as summer winds down, you might want to wander over to the zoo to uncover a few animal tales of your own.

If you get too warm, there's always the movie theater. A TALE OF LEISURE

If they can help it, crocodilians don't move much or fast. Each day, all day, they crawl from water to land and back, from sun to shade and back to sun. They're regulating body temperature. Thirty minutes of watching this can make you pleasantly heavy-lidded. It's hot, it's quiet; you imagine your own life played out between the searing yellow sun and the cool green water.

The zoo's crocodilians live two-thirds of the way down the main path, Olmstead Walk, in and out in back of the Reptile House. The grass-edged pools outdoors look like a crocodilian paradise, what with the still water, the hot sun and the absence of hunters, poachers and motorboats. And the eating is good: two dead rats once a week, which is plenty when you metabolize food efficiently and don't expend much energy keeping warm or hunting for food.

In this idyllic setting, the reptiles revel in their torpor. At 9 a.m. Wally, a female alligator rescued some years ago from a Virginia pet shop, is doing what crocodilians do best: catching some rays. She lies on the shore of her pool, beneath a boardwalk where two visitors stand watching her. Her eyes are open; she's watching, too. Accustomed as Wally is to guests, these two are early and long staying, so she moves slightly closer to the walk.

The minutes pass. The sun gets hotter. Wally blinks. More minutes pass. Half an hour later Wally's still in position.

It's at feeding time that crocodilians live up to their ferocious reputation. One moment, inside the Reptile House, a huge crocodile is collapsed beneath a palm, statue-like. In the next, a keeper behind a cement wall pulls a rat from a green plastic bucket and whistles. The rat is proffered at the end of a long pole, there's a thrashing and an enormous jaw reaches up the cement wall toward its prey. Snap. That rat's gone. The grin, of course, is only an illusion . . .

Outdoors, after a similar lunchtime furor, life slows again. A shy, heat-worshipping Johnston's crocodile has staked out a sunny spot on her shoreline, as far from people as she can get. A large black caiman in her pool mouths her meal tenderly; to stretch a point, she's playing with her food. And Wally, after the meal and a bathe, is prone in the shade, her armored skin dry and dusty-looking, her dark eyes shut. When an especially rowdy bunch clatters her way, she opens them to reassure herself, then veils them once more. She is, luckily, oblivious to the tactlessness of a woman standing nearby, describing in detail how alligator meat is prepared, served and eaten. THE BALLERINAS

After the languor of the crocodiles, you may need a bit of perking up, so head across the park to Beaver Valley. There, at the bottom of the hill, Esther, Jenny, Pearl and Maureen, the zoo's female sea lions, swim in a turquoise pool. They're sleek, acrobatic crowd pleasers, jumping through hoops, retrieving Frisbees and turning flips in the air, in response to their keeper's crisp commands and gestures. In contrast to the crocodilians, the sea lions have a great deal of contact with humans; they're fed several times a day and have half-hour training sessions daily.

As performers, they have personalities and moods. Maureen likes attention, Pearl is a prima donna, Jenny needs encouragement and Esther is reliable and competent. In hot weather, all four get sluggish, although to the uninitiated they appear frisky. Their keeper calls them "the girls."

The girls are fun to watch even when they're playing on their own. They zoom to the deep end of their pool and fling themselves onto a high, craggy rock, then dive back into the water. Esther rolls in the shallows, then strokes over to a low boulder, clambers up and poses, nose to the sky. She joins the others in the water, and they all circle on their sides, flippers in the air, literally cooling their heels -- or what would be heels if they had feet. They look like sharks.

Safe in the pool, the girls seem to be ignoring their fans, but are actually ever alert to what is happening beyond their territory. Although they take the normal din of the crowd in stride, they do not put up with intrusions or unusual events. They are calm with their keepers but suspicious of strangers. Once, when an unfamiliar zoo employee stepped over their fence during a training session, they became too upset to go on with the show. They also fear the far shore of their pool, where dense trees and underbrush block their line of sight. It's on this wooded peninsula, the girls worry, that the bogeyman lurks.

The quartet is especially feisty these days; it's breeding season and they are being kept from their sheik, 600-pound Norman. The zoo doesn't want pups right now; there's a surplus of sea lions in captivity and of orphaned pups in the wild. (Esther and her coterie were orphans themselves.) They take out their frustration on each other now and then, barking and jockeying for position on the rocks. When they make up, though, and swim as an ensemble, they look like a sleek waterborne ballettroupe. OTTER DELIGHT

Animal desire is unchecked a few hundred feet uphill from the sea lions, where the small-clawed otters, Toby and Thai, play. Petite creatures with flat heads and rough-looking, gray-brown fur, the pair is most likely to be seen chasing and courting in early morning or toward dusk.

One warm, quiet, breezy evening, with the romantic aroma of flowers in the air, the bewhiskered duo is running, nipping and squeaking, pursuing each other upstream and down, into their pool and out, through tall grass on shore. After the whirlwind courtship, which makes singles bar action look subtle, they mate; then abruptly Thai lunges at Toby, ending the tender moment. ROUGHING IT

It's Polar Bear Trail that zig-zags through Beaver Valley, taking you to the sea lions and the otters. These days, along a short shady stretch of the trail, you're likely to spot a family of golden-furred monkeys sitting in the trees or scrambling along heavy ropes that serve as bridges from tree to tree, as vines would in the monkeys' native wooded habitat, in Brazil.

The golden lion tamarins -- Celia and Jeremy and offspring Tanya, Josh, Jason and Vern -- look like fugitives and, indeed, they could leave if they wanted to. (They could also be tracked via the small transmitters around their necks.) But the truth is, they don't want to leave; they have everything they need right here, on a one-acre slope. There's a two-story home -- a refurbished beer cooler -- where they sleep at night and retreat when frightened; complimentary meals, hung on various trees; and the convivial company of others of their own kind. Like dudes at a guest ranch, the tamarins have some of the thrill of the wilderness without the danger and loneliness.

The monkeys, who grew up in a zoo and spend much of the year inside, have had to adjust to their free-ranging life, however posh. When they were first brought to Beaver Valley, they slept late and stayed close to the cooler much of the time. When they did venture farther out, they often forgot the way back and had to be shown a route by keepers luring them nestward with bananas. Later, as they became more independent and active, they discovered the low chain-link fence that separates them from visitors, and began to rely on it for travel to and from a favorite insect-studded tree. Having spent time in less natural surroundings, they were used to traveling along rigid paths; vegetation that swayed and bent was strange.

But the monkeys are quick studies; they now balance on branches and scurry along ropes like pros, somersaulting to catch themselves from falling when they misstep. And, on a July day, one of their protectors is establishing an alternative route to the feasting tree, a rope that parallels the fence. The monkeys respond to the human and the ladder in their territory with a series of shrill "eeks," and are reluctant to cooperate immediately. An hour after the rope is installed, only four-month-old Vern is using it, while the others travel boldly atop the fence. Challenged by the rope-hanger to back off the fence, they cock their swarthy faces saucily. Eventually they fling themselves onto a nearby tree.

A father and two small children stop to watch the monkeys scamper. Their pose is respectful. They keep their distance, recognizing the invisible barrier between themselves and the wild creatures just an arm's length away. THE CALL OF THE WILD

The tiny tamarins are playful, social and nimble.

So are the elephants. They play soccer and hunt Easter fruit, cozy up to each other and to their keepers and balance their tonnage on tiny tubs. To watch them is to marvel at Nature's ingenuity. She made them big but gave them the grace and intelligence to manage their size.

The zoo has three of these giant herbivores, Shanthi and Ambika, from Asia, and Nancy, from Africa. While Shanthi and Ambika (Shanthi is the one with more hair on her forehead) are companions, Nancy was raised alone and, at 33, prefers to remain solitary. Years ago, she rendered her opinion of a potential mate by henpecking him mercilessly for a while, then tossing him into the moat that edges her yard.

In general, though, elephants need company. In the wild they travel in herds with a matriarch keeping order. In captivity the keeper plays this role, training the great mammals to respond to her commands. You can see some of the interaction between human and animal during training sessions, when an elephant may be asked to hold up a foot for inspection, to crouch and lie down, to stand on a tub, lift a log, put her toys away. The tasks keep the elephants fit and, in a way, give their lives meaning. The keeper satisfies some emotional needs, too, and elephants become very attached to those who care for them, just as infants bond to parents. When an elephant catches the scent or sight of someone special, it will rumble affectionately.

These animals also are individuals. Ambika, the oldest if not the brightest of the three, will go out of her way to please. Shanthi, an adolescent, is bright, strong-minded and haughty. Nancy, the loner, can be warm and responsive.

You may have to be patient while watching these characters. Shanthi and Ambika sometimes linger teasingly at the door to the Elephant House, and Nancy often stays indoors. But catch any of them in an active moment, and it's fascinating. Silently and swiftly, Shanthi shoos a pigeon out of her way. Ambika plucks marigolds with her trunk, then sprinkles them over her head. And Nancy responds to a midday rainstorm by gliding into her pool and lolling for a good 15 minutes, then emerging to stand in the center of her yard, powdering her back with dust. Alone, great ears flapping and tusks gleaming against her mushroom-colored skin, she is a majestic sight, one that can raise a bit of gooseflesh, no matter how many times you've seen an elephant.

Perhaps more than any other animal the elephants conjure up a sense of the wild. As you watch, the zoo slips away, replaced by images of Asian forests and vast African plains.

THE NATIONAL ZOOLOGICAL PARK is in the 3000 block of Connecticut Avenue NW. Grounds are open from 8 to 8, animal buildings from 9 to 6. (After September 15, animal buildings close at 4:30, gates at 6.) Admission is free; there is limited parking available for $3 per vehicle. The zoo's newest exhibit, the Invertebrate House, is open 9 to 6 Thursday to Sunday; free tickets, available at the Education Building or the exhibit entrance, are usually necessary. The crocodiles are fed on Wednesdays at about 2. Elephants and sea lions (and/or seals) are trained daily at 11:30, unless staff is short. You can check on these and other events at the Education Building or by calling 673-4717 the day of your visit. The otters are outside year-round; the tamarins will be brought indoors sometime in October. For evening zoogoers, there are concerts at Lion-Tiger Hill every Thursday from 6:30 to 8 through August 20.