What foods should I never put in a bird feeder?

There are many foods you should never put in a bird feeder because they can be harmful to birds, attract rodents, or cause disease. You should never put bread, crackers, or other processed baked goods because they offer little nutrition, can swell in birds' stomachs, and mold quickly causing respiratory infections. Never put salty foods like salted nuts, chips, or pretzels because salt is toxic to birds and can cause dehydration and kidney failure. Never put chocolate, which contains theobromine toxic to birds. Never put raw or dry rice, raw beans, or uncooked pasta which can swell inside birds. Avoid milk or dairy products because birds cannot digest lactose. Never put spoiled, moldy, or rancid seeds, nuts, or suet, as mold produces aflatoxins that cause fatal lung infections called aspergillosis. Avoid desiccated coconut which swells inside birds. Never put honey, which can harbor bacteria that cause disease, instead use plain sugar water for hummingbirds. Avoid pet food and meat scraps which attract rats, mice, and predators. Also avoid fruit flavored jellies with artificial sweeteners. The safest foods are black oil sunflower seeds, nyjer thistle, white millet, safflower, unsalted peanuts, and plain suet without additives, along with fresh water.