Suet is a type of fat that is often used in bird feed. It is high in energy and helps birds to stay warm in cold weather. Suet can be bought in blocks or as a powder, and it can be mixed with other ingredients to make bird food. Some people also use suet to make suet cakes, which are fed to birds in the winter. Suet is usually made from beef or pork fat, but it can also be made from vegetable oil. Suet is a good source of energy for birds, and it can help them to survive during cold weather.