Adults form pairs which mate repeatedly throughout the day, often breaking up and reforming in different combinations.

Females leave the aggregations to lay their eggs, which they do by piercing their ovipositor into soft clay on ledges and in crevices within the cave.

[5] At dusk the weta emerge from the cave, seeming more likely to do so when conditions outside are darker (less moonlight) and wetter.

[5] The complete life cycle from hatching to death takes approximately two years.

Many caves inhabited by P. waitomoensis are solutional limestone karst, with active waterways flowing through them.