All living things on the earth need other living things to live with. Nothing lives alone. Sometimes one living thing kills another to live, so they form a food chain.
Plants make food from sunlight, water, air and so on while some animals feed on (以…为食) plants directly. For example locusts (蝗虫) are small insects.
Millions and millions of locusts in a group can eat anything that is green, including a lot of food that people need. In India, locusts have ever destroyed (破坏) many fields of crops. However, locusts can be food for birds, chickens ducks or other living things, even humans.
Humans are at the top of the food chain. They eat not only locusts, but also many other plants and animals. They are members of many food chains, but they often break up the food chains.
Each form of life is linked (和…有联系) to all the others. Breaking the links puts all lives in danger. Humans should share the world with other living things in peace