Gizzard, a digestive organ of birds and certain other animals, such as earthworms, grasshoppers, and crayfish. A bird's gizzard has a thick, muscular wall and often contains gravel eaten by the bird. The food first passes to the crop, or gullet pouch, where it is moistened, then to the proventriculus, or glandular stomach, where it is mixed with mucus and digestive juices. Preparation for digestion is completed in the gizzard, where the food mass is ground by the action of the muscular walls and gravel. In smaller animals, the food usually passes directly from crop to gizzard.The gizzard is a muscular organ of the digestive system of birds and other animals.
Have you ever come home to find your dog waiting patiently for you at the front door? How did he know when to expect you? Do dogs have an understanding of time? Take our quiz to learn about how dogs perceive time.
Snakes can make you afraid and intrigued at the same time. Snakes have slithered over the Earth for more than 130 million years, frequently making appearances in famous narratives from the Bible to mythical stories. This unique animal can swallow animals whole and move across land without any limbs. Take this quiz and learn more about the mysterious snake.