ON A RECENT trip to the National Zoo, Matthew Goldman, age 4, tugged on an anteater's nose as Jamie Crosby, 3, climbed on the animal's back. The mammal was miraculously tolerant; it didn't bite the children, shake them away or flinch. Not far away, Matthew's mother sat calmly, watching the children and the cast bronze anteater.

This enormous anteater, located just outside the Small Mammal House, is only one of many sculpted animals and related works of art at the National Zoo. The zoo isn't just a home for wildlife, it's a zoological art gallery too, and children seem to appreciate the art almost as much as the live animals that roar and run.

A century after its opening, the zoo has made art a big part of its planned expansion. "We're converting the park into a biological park, rather than a zoological park," says Dr. Michael Robinson, director, "and that means bringing in plants and art."

Pedestrians who arrive at the zoo's Connecticut Avenue entrance and walk a short distance to the administration building are greeted by a ceramic wall of jungle animals lining the building's entrance. Across the way, a brightly painted giraffe, zebra, bear and elephant draw attention to a 40-foot-tall glockenspiel clock. (It keeps time but no longer chimes or revolves on the quarter-hour.)

Many of the zoo's larger-than-life sculptures offer tactile amusement for children. The most popular bronze sculptures reveal tails, noses and backs that are especially shiny from constant attention. A family of black fiber glass gorillas, a giant bronze scorpion and a bronze frog reside between the Great Ape and Reptile houses along Olmsted Walk and are perfect for climbing on. The sculptures entertain the children and provide a resting place when walking the slope between animal houses. As her 4-year-old daughter Maxine stepped on the ears of the father gorilla, Wendy Norcross of Bethesda said, "It's a fantasy for them; they can pretend that they're close to the real animals."

While they're out of reach of young hands, other pieces of artwork to note are two 1936 cast aluminum panels located near the entrance to the Reptile House. They feature the Pied Piper luring the rats out of Hamelin, Germany. A series of 40 mosaics of fish, whales, dolphins and other large animals line the rail inside of the Elephant House. They were made in 1987 by art students at Walt Whitman High School in Bethesda from broken tiles donated by local companies.

The latest additions to the park are a 100-year-old willow oak tree into which Steven Weitzman has carved over 40 different animals and a bronze elephant fountain. The two will be officially dedicated and unveiled Thursday. The tree carving, commissioned by the Friends of the National Zoo, is located near the Reptile House. The fountain, featuring an elephant enjoying a spray of water from its trunk, is just outside the Elephant House and was donated by the Twentieth Century Club.

Alexandria-based sculptor Jimilu Mason says she created the fountain with thoughts of a young elephant that died at the zoo in 1984. She opted for the setting of a watering hole rather than a pedestal so visitors could envision an elephant in its natural habitat.

Zoo patron Judy Hutchison of Chevy Chase, heading home after a day at the zoo, said that her daughter Allie Anne, 3, has been an avid zoo sculpture climber since last spring. She had only one question. "Is this legal?" she asked.

Yes, Ms. Hutchison, it is.

THE NATIONAL ZOO -- 3001 Connecticut Ave. NW. 202/673-4800. Free. Grounds open 8 to 6 and animal buildings 9 to 4:30 daily. Metro: Cleveland Park or Woodley Park/Zoo.