Suet cakes or fat balls are nutritional supplements for wild birds used in bird feeders.[1] They commonly consist of sunflower seeds and wheat or oat flakes mixed with suet, pork fat, or coconut oil. Further blends may also contain nuts, fruits, mealworms and other insects.[2]
Next to balls, which are predominantly common in Northern and Central Europe, suet cakes may take various shapes such as rectangles, rings, or wheels. Fat balls are often sold within a fine plastic net allowing their suspension, such as on branches or in bushes. The nets can, however, be a danger to other species, such as deer, who may find the balls and eat them whole.[3] Other forms of suet cakes can be placed within suspendable cages.