1. Staple bird netting (available at hardware and garden-supply stores) over large, round holes, which are signs of nesting.
2. Hang reflective aluminum streamers, such as Irri-Tape, near the damaged areas -- their movement and shine should deter the birds.
3. Hire an insect exterminator if you see small, irregular holes, which indicate an infestation. This way, the birds will forage elsewhere.
Martha Stewart Living, July/August 2014