Nail pops are small holes appearing in your walls when lumber dries out and pushes nails right out of the wall. Nail pops are usually harmless and easy to fix. Simply drive a new nail right next to the loose one. Cover the nail pop with Spackle, repaint, and your wall will look like new again. Don't forget to clean and sand the area first before you add the Spackle, and then use a primer to seal the Spackle before painting over to match the wall.