Reasons why cats eat kittens:
1. If a cat is malnourished and cannot meet the nutritional needs of all its kittens, it will pick out the weaker kittens and eat them to supplement its own nutrition. The owner can feed the mother cat some nutritious food, such as gestation cat food or crucian carp soup.
2. If a kitten smells like another cat, the mother cat may mistake it for her own kitten and kill and eat it.
3. After giving birth, the mother cat suffers a great shock. She believes that the kittens are in danger, and so is she. Therefore, she will eat the kittens to save her life and replenish her nutrition. 
What to do if a cat eats a kitten:
1. First, we must strengthen feeding management. Before and after farrowing, the feed should contain sufficient protein, vitamins and minerals. Feed some foods rich in animal protein, such as fish, beef and pork, and provide plenty of clean drinking water.
2. Do not allow other cats to approach the newborn kittens, so that the kittens may pick up the scent of other cats.
3. When a mother cat is giving birth, she should be given careful care and the environment should be quiet to avoid frightening her.