The best method is to exclude squirrels from gaining access to the feeder(s). Ideally, the feeder should be placed on a pole that is wrapped with aluminum flashing (wrap it like shingles starting bottom to top so the next wrap overlays the first). Adding baffles will help too. But the flashing is too smooth for a squirrel to get a grip. The pole should be at least 10 feet away from tree branches or locations where the squirrel could jump to it. We also suggest the pole be at least 6 feet high.
Some have tried adding capsaicin to the bird feed with some mixed results. Some people swear it works; others say it doesn't.
Employing squirrel-resistant feeders, such as the “Squirrel B-Gone II”, is also a good idea. It is important to employ all the strategies to obtain the best results.
Finally, these techniques will only stop gray, fox, and red squirrels. They won’t stop flying squirrels for obvious reasons. If nighttime predation of your feeder is a problem, then remove the feeder each night.
Resources (online):
Bird Feeders Not Squirrel Feeders
