Invertebrates (animals without backbones) make up about three quarters of all living animal species on earth. In particular, a large proportion of animal species found on oceanic islands are invertebrates because generally they travel across ocean distances more easily than larger vertebrate animals, and Lord Howe Island is no exception to the rule.
Recent intensive invertebrate surveys in 2003 by staff from the Australian Museum recorded more than 1600 species, including 157 land and freshwater snails, 515 beetle species, 27 ants, 183 spiders, 21 earthworms, 137 butterflies and moths and 71 springtails. The invertebrate fauna is characterised by a high degree of endemism, with up to 60% for some groups. Indications are there may be as many as twice this number of species living on the island.