Suet is a high energy combination of animal fat and other ingredients to attract insect eating birds. Suet is a quick source of energy for birds. It has been traditionally used as a good substitute for the insects that birds usually feed upon in cold weather. This low maintenance bird feeder is meant to leave outside, and change the cake as needed. These attractive Britsoleaf covers are made with maple leaves and glazes in white and green. Leaf placement may vary slightly from picture. Each one comes with a suet feed cake.