 The building displays over 140 species, the majority of which are invertebrates.They include leafcutter ants, jewel wasps, golden mantella frogs, brown rats, bird-eating spiders, desert locusts, naked mole rats, leaf insects, moon jellyfish, Polynesian tree snails (Partula), Giant African land snails, cave crickets, fruit beetles and black widow spiders.The Millennium Conservation Centre aims to be environmentally friendly, constructed from materials requiring little energy to produce, and generating its heating from the body heat of both the animals and visitors.