If you have stepped outside across eastern Australia recently, you might have noticed a flurry of brown nocturnal visitors resting under outdoor eaves, gathering near porch lights, or sheltering in quiet garden spots. Reports are pouring in across New South Wales, the ACT, and Victoria of a significant increase in Bogong moth (Agrotis infusa) activity this season.

The droughts between 2017 and 2019 resulted in a severe population crash and a listing on the Endangered species list. Numbers dropped by up to 99.5% during this time was due to severe inland drought and warming temperatures.Seeing these resilient insects return in large numbers is an encouraging sign for Australian biodiversity.
Australia’s Great Insect Migration
Each year, millions of Bogong moths undertake one of the most extraordinary journeys in the natural world. Hatching in the agricultural plains and inland cracking-clay soils of the Murray-Darling Basin, adult moths emerge in early spring to escape the rising summer heat.
Their destination? The cool, high-altitude caves and granite boulder fields of the Australian Alps and Snowy Mountains.
What makes this journey mind-boggling is that every generation completes it without instruction from their parents. Navigating hundreds of kilometres using Earth’s magnetic fields and starlight, the moths fly to the high country to enter aestivation—a state of summer dormancy—before returning inland to breed in autumn.
Why Their Recovery Matters
The recent uptick in sightings—with hundreds of observations logged on citizen science platforms like iNaturalist over just a few days—brings vital ecological benefits:
- Essential Food Source for Alpine Wildlife: Bogong moths are exceptionally rich in fats and proteins. They are the primary food source for the critically endangered Mountain Pygmy-possum (Burramys parvus) when it wakes hungry from winter hibernation.
- Nutrient Transporters: By migrating in massive numbers, moths carry key nutrients up into fragile alpine soils and aquatic food webs.
- Inland Moisture Signals: Favourable winter rainfall in breeding grounds likely boosted caterpillar survival rates, giving the population a much-needed break from drought conditions.
- Deep Cultural Connections: Bogong moths hold thousands of years of cultural significance for First Nations groups, who traditionally gathered in the high country during summer to harvest them as a rich food source and gather for ceremonies.
Simple Ways You Can Help Migrating Moths
As these nocturnal navigators pass through towns and cities, light pollution and urban hazards can throw them off course. Bright artificial lights disorientate the moths, leading to exhaustion before they reach their alpine destination.
Here is how you can help give Bogong moths safe passage this season:
- Turn Off Outdoor Lights: Switch off external lights and pull blinds closed at night to prevent disorienting migrating moths.
- Avoid Chemical Sprays: Skip pesticides around your house and garden.Bogong moths are completely harmless to people and property.
- Log Your Sightings: Help researchers track migration pathways by logging sightings on iNaturalist or Zoos Victoria’s Moth Tracker app.
- Create Habitat: Plant native flowering species in your garden to provide nectar and shelter for resting travellers.
Every small effort in our backyards helps ensure these incredible creatures complete their remarkable journey across our landscape.























