Something's happening at the zoo. A man is living there in the tortoise paddock. Just for the weekend, mind you, but the Galapagos tortoises who are kindly sharing their turf with him were a bit nonplused at first. They almost knocked the human beast out of his black leather armchair. But they will adjust.

Normally, the Miami Metrozoo is the sort of place where elementary school teachers drag rows of riotous children behind them and lecture on the diet of the white Bengal tiger and the mating habits of the black and white ruffed lemurs.

A school trip to the zoo took on a new dimension today with the addition of Homo sapiens urbanus. Albert Vidal, a 38-year-old actor who lives in the Spanish Pyrenees, has descended from that rarefied air to take up residence here as "Urban Man." Hundreds have come to see his stunning "performance."

"It's as if from an extraterrestrial planet one selected a specimen to present to the public here as something interesting," Vidal said before his three-day pantomime of everyday life began. "It's the same as seeing a camel or any other species in the zoo."

For a fee of $10,000 Vidal is brushing his teeth, eating fast food, chatting on the phone, watching television and riding an exercise bike. He wears a black suit by day and striped pajamas by night. The paddock is packed with all the appropriate furniture. By the looks of the sleek platform bed, huge color television and VCR and a high-tech desk, this "Urban Man" on display here is a sort of Euro-fied yuppie. Vidal, who is a well-known performance artist, mime and actor in Europe, lingers in slow motion over every ordinary gesture. The way he straightens his shirt collars, the way he sips a Coke, the way he pores over a copy of Advertising Age draws howls from the crowd.

"It's something very common," Vidal says of his activities, "but I present it as if it were something full of interest . . . There are so many interesting things in day-to-day life."

The children who line the rail are amazed at this flurry of ordinary activity. The lemurs, gibbons and albino tigers will have to wait until Vidal leaves on Sunday night to regain center stage. Children call to Vidal to work his magic. "Brush your teeth!" they shout. Or "Drink from the cup!" Or "Make a phone call!" These children, though, seem to have an innate sense of privacy and ask him to do nothing that they would not be able to see done on television. Indeed, Vidal has a private bathroom and if it rains, he'll be able to sleep in one of the zoo's houses.

"Now I know what I want to be when I grow up," said Sam Beckman, who is 7 years old. "I want to be the guy in the zoo."

Sam's mother, Yvonne, explained that no, this was only a "semi-normal event" and that being the "Urban Man" in the zoo was, perhaps, an inappropriate professional ambition. Sam went back to the rail, unperturbed, to feed "Urban Man" some candy and pet his black polyester suit. Sam loved it when "Urban Man" leaned back in his desk chair and sprayed the South Florida air with wintergreen room freshener. The tortoises were unfazed.

"The kids here think this is the most amazing thing of all time," Suzanne Preshong said as she marshaled a huge group of day-trippers from the Small Fry Camp to the next exhibit. "I guess it's not everyday you see a guy in the zoo."

Some of the children show an understandable impatience with the art of pantomime and are upset that Vidal will communicate with them only through gesture and the distribution of business cards.

"How come he doesn't talk?" said a querulous 5-year-old, Holly Nobile. "I guess he had an operation or something."

Or something. It takes time to understand the vagaries of art.

Like any beast at the zoo, "Urban Man" has an enameled plaque that describes him: "Urban Man, reputed to be the most intelligent of the primates, is found in a variety of social groupings. Aggressive at times, some members of the species pair for life, while others are polygamists found in cities throughout the planet, man extends his territory to places he calls high rises, discos and fast food restaurants."

Miami has experienced this sort of performance before. Last year, the Hungarian-born artist Christo wrapped several islands in Biscayne Bay with pink plastic cloth and the Israeli artist Yaakov Agam painted a high-rise condominium in a rainbow of colors.

Metrozoo and the Miami Dade Cultural Affairs Coordinating Committee are splitting the cost of Vidal's performance. His ideas spring from a number of cultures and performance traditions. Vidal studied mime in Paris, oriental religious theater in Indonesia and avant-garde dance in Japan. When Vidal was asked to perform at a theater festival in Spain last year, he found himself sapped of inspiration.

"I told the director all I can do is walk and sit in a chair and eat in a restaurant. That's all I can do right now," Vidal said. " The director said, 'All right, so do that.' "

The Spanish audiences, like the ones here, were transfixed by the display of the ordinary. One little boy in particular could not take his eyes off Vidal in Barcelona. "Why are you so calm?" Vidal remembers the mother asking her child. "Here you are watching the man do exactly what your father does at home all the time, but around your father, all you do is scream."