Why Bogong Moths Migrate to the Australian Alps

Why do bogong moths travel to the Australian Alps?

Bogong moths make a long seasonal journey to escape the heat of summer. They fly to cool caves in the Australian Alps, including the Snowy Mountains in southern New South Wales, and shelter there while conditions inland are hot. The journey can be as long as 1,000 kilometres. ¹

The mountains are not their permanent home or their breeding destination. After sheltering, the moths return to inland Australia to mate and lay eggs, then the cycle begins again. ¹ The migration is one part of a life cycle that links inland breeding areas with summer refuges in the mountains.

How do bogong moths find their way?

Bogong moths are nocturnal: they are active at night. One account of their migration says they navigate by following the stars. ¹ That gives a simple explanation for how a night-flying insect can travel such a long distance, though the sources available here do not provide detail on how scientists established this or what other cues the moths may use.

The journey is not always a direct trip without pauses. In 2026, reports described moths stopping in places along the way, including homes and other built-up areas. A Zoos Victoria conservation biologist said the trip to the Alps may take days to weeks. ³ Moths drawn to bright lights can also gather around buildings: during the Sydney Olympics closing ceremony in 2000, stadium lights attracted so many that radar showed what looked like an approaching storm. ¹

What happens to the moths in the mountains?

The caves offer the cool summer shelter the moths seek. They gather there during the warmer season, then head back to inland Australia to breed. ¹ The available sources describe the refuge and the return journey, but do not give a detailed account of how long individual moths stay or how conditions inside the caves affect their survival.

The moths matter beyond their own migration. Animals feed on them, including the critically endangered mountain pygmy possum, which is one reason the moths’ arrival in the Alps is ecologically important. ³ A large migration can provide food for wildlife that depends on the moths, but the sources do not quantify how much of those animals’ diet the moths make up.

What does the recent rise in moths mean for nature?

Recent reports describe many more bogong moths than in some preceding seasons. On October 13, 2026, 7NEWS reported that a Zoos Victoria Moth Tracker had recorded 12,000 verified sightings, about six times its previous best seasons. ³ That is an encouraging sign of activity, but it is a record of sightings submitted to a tracker, not by itself a full census of the moth population.

The rise is notable because bogong moth numbers had fallen sharply in earlier years. A 2026 article in The Conversation reported a 99% decline between 2017 and 2019. ¹ The same article described the current resurgence as useful information for scientists studying the population. A return of moths may therefore be promising, but the reports provided here do not establish why numbers have increased or whether the recovery will last.

A single busy season cannot answer every question about the species’ longer-term health. The recent reports suggest that moths are moving through populated areas and heading towards the Alps, where wildlife can feed on them. ³ To understand what this means over time, scientists need to track numbers and migration patterns across seasons.

What should people make of moths turning up at home?

A bogong moth appearing in a home or shopping centre can be an unexpected part of its migration. Reports in October 2026 described millions of moths on the move and large numbers showing up in populated places. ²³ Their presence indoors does not, on its own, tell you how healthy the whole population is.

The reported rise has been described as encouraging for nature, but the moths’ arrival may also be inconvenient for people. ³ The sources here do not provide detailed guidance for managing moths indoors, so this explainer does not recommend a particular method. For information about sightings, the Zoos Victoria Moth Tracker was cited in the October 2026 report. ³