As I sit outside this evening, the sun is just slipping behind the wooded hills of Kozara National Park. The sky turns that perfect dusky pink, the kind that makes me reach for my camera, though it never seems to capture the colours quite right. I must work on that.But tonight isn’t about the view. It’s about the sound.Not the familiar birdsong, the bark of a village dog, or even the faint whir of a distant tractor.No, this evening’s soundtrack is coming from underground.Meet the Mole CricketAround this time of year, late July, something remarkable happens just below the surface of the soft, river-fed soil we have all around us.A gentle, rolling trill begins to rise from the earth. At first, it sounds faint, almost electronic. Then, as the minutes pass, others join in, and the entire area begins to hum.