阅读理解
In nature, you may see many insects and animals of different colours. Have you ever wondered why?
Locusts are super delicious food 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 colours of locusts change with the colours of crops. When crops are young, locusts look green. But when autumn comes, locusts change to the yellow and brown colour as crops do.
Brown bears, tigers and other animals move quietly through forests. They can't be seen easily by their enemies. This is because they have colours 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 colourful like flowers. Soil insects are mostly dark coloured and they live under the soil in a dark and wet environment. However, insects with colours different from plants can easily be found and eaten by others. So in order tosurvive, they have to hide themselves in the daytime and appear only at night.
Have you ever noticed some even stranger acts? The ink fish in the sea can send out some very black ink when it faces danger. As the ink spreads over, its enemies will find themselves suddenly in a dark world. At the same time the ink fish immediately swims away. That is how it keeps itself safe though it is not strong at all.
