"Maybe this is just their bathroom and they live somewhere else," suggested six-year old Tabitha, side-stepping what she euphemistically called "signs" of the famous wild ponies on the pony trail at Chincoteague National Wildlife Refuge on Assateague Island.

We had almost completed the 1.6-mile loop through the loblolly pine woods and even climbed an observation tower, but all we had seen of the ponies were these signs. Spending a fall weekend in Chincoteague, we hoped to see the horses when they were free of the seperation anxieties surrounding the pony penning in July.

"Where's Big Bopper?" asked three-year-old Caroline, referring to a nickname a National Geographic writer and photographer had given one of the ponies in a children's book.

My husband, who was striding ahead, suddenly motioned us to stop and a small Sika deer crossed the path in front of us. The deer, a descendant of Oriental deer released here in the 1920's, lept into the woods and stared at us inscrutably from behind a tree.

"I got him, daddy!" cried Tabitha, clicking her Instanmatic triumphantly.

Before she had time to advance the film, our real quarry came into view: Nine horses and a young foal hurried across the path.

"Which were the Mommy and Daddy?" asked Caroline.

The daddy, we explained, was undoubtedly the stallion who was bringing up the rear. The mommy could have been any one of the mares in this typical wild-horse nuclear family.

The animals travel in bands of three to 20, according to Ronald Keiper of Pennsylvania State University, who has been studying the behavior of the ponies since 1975.

"There is rarely more than one adult male in a band," Keiper said in a telephone interview, "although there are some bands where two or three young males are co-dominant.

"Young male colts leave the band between their first and second years. One of the things I'm studying is what causes the animals to leave the band. Do they leave on their own or are they picked on by their father until they leave? tI've seen young males picked on but never actually chased out."

Young fillies usually leave their parents, too, but not always according to Keiper.

"I'm studying a daughter bred to her father who's produced an offspring," said Keiper."So far the young animal seems healthy. Most young females leave the band. This may be a built-in evolutionary mechanism to prevent in-breeding. The females aren't forced to leave. They leave on their own and eventually meet up with a stallion.

"There are some mares that I call liberated: They leave the stallion and wander by themselves. I'm also studying the relationship among siblings," he said. "I've been following three brothers. Two now have their own bands of mares, and one is a bachelor group. I want to see whether they'll eventually fight over mares or whetehr they'll get along better because they remember each other."

The ponies, said Keiper, are so used to people that they don't mind being observed and go about their business as if no humans were arond -- once they figure out that you're not going to feed them. The Chincoteague herd, about 130 head, is owned by the Chincoteague Volunteer Fire Company. Nobody feeds them -- in fact feeding the ponies is strictly forbidden by the park service -- and that's what makes them wild. They survive on their own, eating shrub leaves and dune and marsh grasses and drinking water from brackish ponds. Since this diet is low in nutrition, the horses are small -- about the size of a Welsh pony.

Nobody knows exactly how the ponies got to Assateague. Legend says the original horses swam to the island from a shipwrecked Spanish galleon. A rival story says they were placed there by pirates. An economic theory says the horses were exiled to the barrier islands when 17th-century colonial legislatures enacted laws taxing livestock.

When we got out of the woods and off the pony trail, we saw lots of ponies. Some clomped along the road, causing mini-traffic jams to the sound of cameras clicking. Most grazed on the marshes.

Since our kids were tired after the 1.6-mile pony trail, we decided to do the 3.5-mile loop around Snow Goose Pool by car. Known as the Wildlife Drive, the loop is reserved for pedestrians and bikers most of the day but open to cars after three in the afternoon. Edging past the serious naturalists who had set up sophisticated spyglasses to watch for waterfowl, we made our way around the fresh-water pool, pointing out herons, egrets and other easily recognizable birds. For the kids, the highlight of was a band of wild ponies grazing by the pond.

"Look at that birdie riding the horsey!" cried Caroline.

By way of explanation I made up a story about how the bird had once found a foal who was lost in the woods and how in return the now-grown-up horse gave the bird rides. The real explanation, I learned later from Keiper, is that the egrets have a symbiotic relationship: The egrets eat the ticks, mosquitoes and horseflies that pester the ponies.

According to Keiper's research, however, the birds get more to eat if they stay on the ground a distance of three feet or more from the pony than if they sit on its back.

If you spend a fall weekend at Chincoteauge with young children, the first order of business will probably be to see the ponies. Here are some things you can do after that:

Take a walk along the ocean and look for seashells.

Sign up for the night wildlife safari at the visitors' center and stalk wildlife in a van.

Make reservations at the visitors' center for a narrated boat cruise through Assateague Channel.

Hike to the lighthouse and see an art exhibit in the adjacent shed.

Take Tom's Cove Nature Trail and view the ruins of a fish-oil and fertilizer factory.

Visit the Oyster Museum.

Go to the Chincoteague Miniature Pony Farm and see the famous Misty of Chincoteague (stuffed) and her grandson Cloudy (live).

Stop in at Russell's Seafood on South Main Street and watch the fishing boats unload.

Get up early in the morning and walk to the bakery on Main Street. It opens at 6 to sell donuts and Danishes that were baked even earlier that morning.

Books to read to your kids before you go: "The Island Ponies" by Barbara Ford and Ronald Keiper (Morrow); "Misty of Chincoteague" by Marguerite Henry (Rand McNally); and "The Wild Ponies of Assateague Island" by Donna K. Grosvenor (National Geographic).