As their name implies, peanut feeders house shelled or in-shell peanuts with large enough openings for birds to peck out the large legumes. Many of these feeders rely on a spiral of metal to form a cylinder, cone or wreath shape. Peanuts can be loaded through a lid at the top of the feeder. The result is a simple but elegant feeder. A peanut feeder with a tightly coiled wire is ideal for shelled peanuts, while a looser coil provides the right resistance for peanuts in the shell.
In addition to wire coil style, some peanut feeders feature a wire cages. Still other peanut feeders look like a traditional bird feeder with a glass window to show off the tasty treats, a platform for perching and an open slot to which gravity pulls the nuts.
In addition to attracting larger birds like jays, peanut feeders appeal to smaller birds like tits and finches. Woodpeckers and nuthatches, who are adapted to peck along a tree trunk to find their meals, will also enjoy the challenge of extracting whole peanuts from holes drilled into a log. Some bird lovers also find peanut feeders to be a useful distraction to squirrels who might otherwise raid their other feeders.
While humans and birds both enjoy the same snack, it is important to always fill peanut feeders with unsalted nuts, as birds are unable to digest the excess sodium in seasoned nuts.