Just got through patching and painting this years woodpecker damage. Not a happy camper as the holes were so large and deep that the patching compound sort of sucked in as it dried. I'll have to repatch and repaint those areas again in the spring.
Freezing paintballs do not work...they expand and will not go down the barrel and make a mess,and once the thaw out the absorb any moisture on them and expand.
Paintballs are lethal when used against smaller rodents, and would also probably be damaging (as in wander off an die later) to birds. No need to freeze them.