Why endangered Bogong moths are swarming Australia's east coast

An influx of Bogong moths has caused a stir along Australia's east coast, with residents in cities including Sydney and Canberra reporting large numbers of the insects appearing in their homes and cars.

The sudden swarm has prompted many people to film the moths as they make their way into buildings and vehicles, sharing the footage widely and drawing attention to the unusual scale of the phenomenon. Bogong moths are known for undertaking long migratory journeys, and the species has previously been classified as endangered.

The appearance of large numbers of the moths in urban areas has raised questions among residents about what is driving the swarm and what, if anything, it signals about the health of the species' population or changes in its migratory patterns. Bogong moths have ecological significance in Australia, including as a food source for other native species in parts of the country.

While swarms of moths are not unprecedented, the scale of the recent influx appears to have been notable enough to draw widespread public attention and media coverage across the affected cities.

It is not yet clear what longer-term factors may be contributing to the swarm's size, or whether similar influxes are expected to recur in the future.