Feral cats should be caught in live traps and turned over to the local animal control officer. Place your feeder and bird bath a minimum of eight feet from bushes, trees, or other hiding places where cats can wait to prey on visiting birds. Squirrels These persistent little animals will take over a feeder and prevent birds from eating. Squirrels will have no problem leaping to a feeder that is within 6 feet of a tree. You can also place an umbrella-shaped guard on your feeder as shown in the example below.
Squirrels can easily chew through plastic and rope.
If you buy a tube feeder, make sure the feeding ports are reinforced with galvanized steel. Hang your tube feeder with wire or braided fishing line, not rope or string. House sparrows, starlings, and grackles are three birds that you do not want to attract to your feeder. Each of these three species travel in flocks and are very aggressive towards other birds. It is not uncommon to see 50 house sparrows or grackles raiding your feeder while chickadees, nuthatches, and siskins wait in a nearby tree to get a chance to feed.