A new study published in the journal Nature reveals that Australian Bogong moths use both the Earth’s magnetic field and the night sky as a compass during long-distance migrations, making them the first insects to be found to do so. The research, led by neurobiologist Eric Warrant of Lund University in Sweden, used a flight simulator to test the behavior of captured moths, allowing scientists to understand how these small creatures navigate their incredible journeys.
Bogong moths travel approximately 600 miles from their breeding grounds to alpine caves in the Australian Alps during the summer and return to their breeding grounds in the fall. The insects’ ability to migrate such vast distances has puzzled scientists for years, with many wondering how they use visual cues and magnetic fields to navigate their route.
The study found that when the Earth’s magnetic field was removed from the simulator, the stars and Milky Way were sufficient for the moths to orient themselves during flight. If the projected sky was turned 180 degrees, the moth would also turn. This suggests that the insects use a combination of internal compasses, one guided by the Earth’s magnetic field and the other by the night sky, to reach their destination.
The researchers inserted tiny electrodes into the moths’ brains to measure the neurons’ response to the same starry sky that provoked the behavioral response, confirming that the neural responses matched the behavior. This discovery opens up new avenues of research, including how the magnetic and night sky compasses work together and whether one is more dominant than the other.
The study’s findings are not only a testament to the incredible navigational abilities of Bogong moths but also highlight the complexity and sophistication of their brain networks. As Dr. el Jundi noted, “the brain network and the ability of these animals to perform quite extraordinary and complex navigational tasks is just mind-blowing.”
Source: https://www.nytimes.com/2025/06/18/science/moths-celestial-navigation-australia.html