[3] Although it had been extirpated from Lord Howe itself, a remnant population of 24 individuals was rediscovered on the sea stack of Ball's Pyramid, and the species has been called "the rarest insect in the world".

Adult Lord Howe Island stick insects can measure up to 20 centimetres (8 in) in length and weigh 25 grams (1 oz), with males 25% smaller than females.

[6] However, in 1964, a team of climbers visiting Ball's Pyramid, a rocky sea stack 23 kilometres (14 mi) south-east of Lord Howe , discovered a dead stick insect.

[7] In 2001, Australian scientists David Priddel and Nicholas Carlile hypothesised that there was sufficient vegetation on the islet to support a population of the insects, and, with two assistants, travelled there to investigate further.

On their descent, the team discovered large insect droppings under a single Melaleuca shrub growing in a crevice approximately 100 metres above the shoreline.

[3][7] In 2003, a research team from New South Wales National Parks and Wildlife Service returned to Ball's Pyramid and collected two breeding pairs, one destined for a private breeder in Sydney and the other sent to the Melbourne Zoo.

[7] The ultimate goal was to produce a large population for reintroduction to Lord Howe Island, providing that a project to eradicate the invasive rats was successful.

In 2008, when Jane Goodall visited the zoo, the population had grown to 11,376 eggs and 700 individuals,[7] 20 of which were soon after returned to a special habitat on Lord Howe Island.