I once camped on a wooded site in Cornwall, and was woken by the sound of woodpeckers drumming, so I got up at about 5, and they were all over the place. An hour later, all was quiet, and you'd never have seen them unless you were really looking, as they stay up in the trees. When I went for a walk through the oakwoods later, I could find them by scanning the high branches with a pair of binoculars. I hear them drumming every year in a patch of woods by the allotments, but they're hard to see.
