It is well known that honey bees use the position of the sun to navigate to flowers and then find their way precisely back to the hive.
But what happens on cloudy days, when the sun is hidden, or deep inside a forest?
Scientists have discovered that honey bees can also sense Earth's magnetic field. When the sun is obscured by clouds, they are thought to use this magnetic field as a secondary compass to help guide their flight.
Even more remarkably, inside the dark hive where no sunlight reaches, honey bees can use Earth's magnetic field as a reference when building their beautiful, perfectly aligned hexagonal honeycomb.
In recent years, researchers have also been investigating whether artificial electromagnetic fields—such as those generated by high-voltage power lines and mobile phones—might interfere with bees' magnetic sense. Although the evidence is still inconclusive, some studies suggest that exposure to certain electromagnetic fields may affect bees' ability to navigate and forage efficiently.
While most of us never notice Earth's invisible magnetic field, honey bees may be using it every day as they travel from flower to flower.
Perhaps one of nature's smallest navigators carries a compass more remarkable than we ever imagined.