In nature, you may see many insects and animals of different colors. Have you ever wondered why? Locusts（蝗虫）are super delicious f for birds, but it is not always an easy job for birds to catch them. It is neither because locusts are good jumpers or runners nor because they are smarter than their enemies. The reason is that the colors of locusts cwith the colors of crops. When crops are young, locusts look green. But when autumn comes, locusts change to the yellow and brown color as crops do.
Brown bears, tigers and other animals move quietly through forests. They can't be seen e by their enemies. This is because they have colors similar to the trees. For the same reason, polar bears that live on a land of snow and ice are white. Butterflies and bees living among the flowers are colorful like flowers. Soil insects are mostly dark-colored and they live under the soil（土壤）in a dark and wet e. However, insects with colors different from plants can easily be found and eaten by others. So in order to s, they have to hide themselves in the daytime and appear only at night.
Have you ever noticed some even stranger acts? The ink fish（墨鱼）in the sea can send out some very black ink when it faces danger. As the ink spreads over, its enemies will find t suddenly in a dark world. At the same time the ink fish immediately swims away. That is how it keeps itself s though it is not strong at all.
