The pound;4m-plus building, part-financed by the Millennium Commission, houses The Web of Life exhibition. This displays bio-diversity through myriad invertebrates and other creatures. Invertebrates make up 97 per cent of the animal population and without them most other life forms could not survive. Yet many species are under threat.
A dramatic sculpture of a giant dung ball complete with dung beetles is outside the entrance but the first indoor exhibit really draws a crowd: a colony of leafcutter ants. Individuals may be seen carrying scraps of leaf vastly larger than themselves along ropeways to the nest. We are informed that a colony can number between five and eight million ants.
Close by, a swarm of desert locusts crawling over an old jeep produces a strong "yuk" reaction - you may be relieved to know that, unlike the leaf-cutter ants, this exhibit is behind glass. Many exhibits require close inspection as the creatures' camouflage is so complete you could easily miss them.
Access is inviting and a carpeted ramp shows that the needs of infants, buggy-pushing adults and those in wheelchairs have been accommodated.
There are more than 60 exhibits featuring some 140 species in a variety of settings. In the micrarium, said to be the tiniest zoo in the world, there are minute creatures not usually seen by human eyes such as brine shrimps, soil mites and roundworms. Birdsong sets the scene for a mini-rainforest populated by tamarin monkeys, tarantulas, scorpions and giant millipedes. Seagulls and whale song provide background noises to the ocean life section which includes giant clams, a living coral reef and moon jellyfish. The complexity of a spider's web and the dazzling beauty of butterflies are other enchantments. You can also see mole rats if you wait long enough.
There is copious information alongside the exhibitions. Some of it is light-hearted, like the suggestion beside the jellyfish to spot the jelly babies. The core message, however, is about how truly astonishing these creatures are and how they can be protected.
The new Activity Den linked to the building is open to families in the afternoons and at other times provides space for school groups.
London Zoo, Regents Park, London NW1. Tel: 0171 449 6552. Open daily, 10am-5.30pm, from 1 November 10am-4pm. For group bookings call Rebecca Westerland, education department.