“It,” in this case, being a ball of dung:
Once a beetle (Scarabaeus satyrus) has constructed its dung ball, it moves off in a straight line in order to escape from rival beetles as quickly as possible, lest they try and steal its carefully crafted ball. This behaviour doesn’t sound complicated, but several years ago, Marie Dacke of Lund University in Sweden and colleagues showed that polarised light from the moon is important for dung beetles to keep to a straight line.
Take away the moon, and the beetles should careen wildly down the trail, right? Wrong. It’s not the moon at all:
By switching stars on and off, Dacke discovered that the glowing strip of the whole Milky Way was what guided the beetles’ movement. “Before it was assumed insects could not use the stars because their eyes don’t have the resolution to see them,” she says. Navigating using the whole of the Milky Way does away with the need to see individual stars.
There’s something sort of enchanting about this, as though the stars were going out of their way to make life easier for bugs.
(Via Bayou Renaissance Man.)