Hulled sunflower seeds can be purchased whole or as chips, sometimes called hearts. The whole kernels are the most desirable, of course, but the pieces are still attractive to birds and both forms are used in many wild bird seed mixes.Hulled sunflower seeds are rich in oil and a high source of calories for birds, making them a popular feeder option. They are more expensive than regular sunflower seed but may be more economical when purchased by weight because there is no waste. Hulled seeds will not grow if spilled on the ground, making them a favorite for backyard birders. Their rich nutritional content and fresh flavor make them an excellent snack on their own, or they can be added to trail mixes to enhance taste and nutritive value.