...'ere being the operative word. Well actually 'hear'
I watched this Great spotted woodpecker this morning after hearing it. Not pecking or drumming but scratching the branches with his claws and then listening for movement of a likely snack moving beneath the bark. I often hear the tell-tale sound of birds with similar claws scuttling about on the bark; Tree creepers and Nuthatches especially, and can tell them apart before seeing them.
"How can you hear such subtle differences, not to mention the faint noice?" I'm often asked.
First you have to want to. Don't just listen, hear!