!@?%! Woodpeckers

So this weekend Paul noticed that we have had more holes appearing in our trees, (2 in front in 1 in back). So he asked if I would take a picture and go to the garden center and ask if they knew what it was and how to treat it. I did. Yesterday armed with a picture of the trees I asked the man at the garden center what it was with out even looking at the picture he said, "woodpecker!" I told him the holes are in a perfect line around the tree. He said there is not anything I could do about them and I left feeling deflated. I looked it up on the Internet and I think we will try to hang some aluminum pie tins in the trees to try to ward them off. The guy at the garden center said he has been seeing a lot of them right now and mainly in the live oaks (our 3 trees). My hypothesis is that since we have been having colder than normal weather this winter there are not as many bugs so the woodpeckers are going in search of food. I just hope that the pie tins work and they will find another tree to destroy!! If you know of anything that works please pass it along...