One important thing about delicate astronomical equipment is that it works better when it’s clean. So when birds start hanging around sensitive tracking antennas designed to communicate with far-off space probes, like the comet-chasing Rosetta, space agencies get a little nervous. But birds with loose bowels looking to leave some treasure behind at the European Space Agency’s Cebreros tracking station in Spain have a formidable foe: a falcon named Nalla. 

The ESA dubs it “the medieval art of falcon persuasion.” Nalla, a peregrine falcon, comes around with her handler every once in a while to scare off local birds that might think of a giant communications antenna as an attractive place to nest or pause for a bathroom break. The wild birds that might otherwise want to take up residence are too wary of the winged predator to stick around. Unfettered by poop, the antenna is free to signal to spacecraft up to 500 million miles away.