How can I prevent any future woodpecker holes in my siding?
Research shows most deterrents for woodpeckers typically do not work. One proven foolproof way to stop woodpecker damage is to install netting on your home. Sometimes the visual deterrents do not work well because woodpeckers can figure out there's no actual threat present and will get used to the new addition.
There are a variety of woodpecker deterrents available to try after you have completed your repairs. First, protect trees by mounting bird-repellent tape to tree trunks or hanging old mirrors from limbs: the shiny, reflective surface will scare off nearby woodpeckers. You can also hang windchimes, plastic owls or hawks from tree limbs or siding or eaves of the home to frighten any woodpeckers in the area. Lastly, if you have a dead tree in the yard, consider hanging a suet feeder to lure the birds to the dead wood and preserve living.