Tube feeders are made to hold either sunflower or mixed seeds, thistle or nyjer seed, whole peanuts, or shelled peanuts. Some birds perch and some birds cling, so it depends on who you’re looking to attract.
Clinging birds for example, like Chickadees, Nuthatches, Titmice, and Woodpeckers will frequent tube birdfeeders that offer shelled peanuts. They have strong feet, and are known as “polite” birds, because they tend to take one seed and fly away to eat, or store it. They’re most entertaining to watch with their aerobatic antics. and, as a group, clinging birds are quite desirable to have around your patio, deck, or even window!