Be quiet to get close to feeding Silver Ys

A still, balmy night, there are many Silver Y moths feeding on the garden flowers: lavender, perennial peas and buddleia. I always have trouble taking photos of the Silver Ys, they are so flighty! A step forward and they all disperse. A typical shot when I am outside is like the one above. My best shots have always been from behind the conservatory window. Today I understood why. If found out that you want to get close to these moths you need to be quiet. Why did this surprise me? I knew moths are able to hear bat ultrasounds and respond with erratic flight and even dropping to the ground, I even wrote a post about it. But there is nothing like first hand experience for learning. I tried to take shots from the cloud of silver Ys feeding in the buddleia tonight, they were visible in the dusk light as hovering silouettes by the profile of the large flowers. And then, as I approached, camera pointing up and triying to decide which one to shoot, I stepped on a crunchy leave inadvertently. The whole cloud of moths responded instantly by flying in different directions: of course they can hear! Many sounds we make while moving about are actually ultrasounds (click your fingers near a bat detector to test this). I bet walking on my pebbly path does this too, and this was what was keeping them away. I moved slowly, placing each foot carefully and slowly on the ground. Stood next to the buddleia and waited until the silver Ys came back and resumed their feeding. And this time managed some outdoor clear shots.