Billions of Bogong Moths Swarm Australia's East Coast

An extraordinary natural event is unfolding across Australia's east coast, as billions of Bogong moths take part in their annual migration south to the cooler high country of the Snowy Mountains. Some estimates put the number of moths involved at around 2.2 billion, with an official tracking map showing the swarm spreading down the coastline.

For scientists, the migration is a remarkable feat of navigation. The moths travel hundreds of kilometres, using the stars to guide their journey to alpine caves where they shelter over summer. Researchers describe the ability of a small insect to navigate such distances with such precision as genuinely extraordinary.

But for many residents caught in the moths' path, the experience has been closer to a horror movie than a wildlife documentary. Social media has been flooded with footage of homes overrun by moths, with some residents saying the insects have made it almost impossible to sleep. Videos show the moths going door to door, seemingly with nowhere for householders to escape them.

The scale of the swarm has even prompted an official response from the State Emergency Service, which has said it may need to start referencing moth plagues in future public alerts. The organisation also marked the event with a lighthearted poem about a fictional moth named Barry, in an attempt to bring some humour to the disruption.

Despite the frustration of those living through the swarm, experts stress the moths play a crucial ecological role. Bogong moths pollinate native flowering plants and are a vital food source for the endangered mountain pygmy possum, one of the few mammals in the world known to hibernate. A poor moth season can have flow-on effects for the possum population in the alpine regions where both species live.

Mass moth migrations are not without precedent. Sydney experienced a similarly dramatic swarm during the 2000 Olympic Games, when the bright floodlights of the stadium drew in huge numbers of moths, creating an unexpected spectacle during what was dubbed the best Games ever.

With the current migration well underway, authorities and wildlife experts are urging people not to panic or reach for insect spray. The advice for anyone finding moths in their home is simple: catch them gently and release them outside rather than killing them, given their importance to the wider ecosystem. As the swarm moves through, many are being encouraged to see the moths off with a measure of respect, rather than revulsion, for a journey that few other creatures could complete.