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    When you watch TV programs about wild animals, it is surprising to see how an antelope (羚羊) can run away from a strong lion. In the wild, everyone has his own way to protect himself. Even plants have their own ways to fight against their enemies.

    Over millions of years, plants have developed their own way to protect themselves. Chemicals (化学物质) are used by plants to live. By making their leaves, flowers, roots and fruits poisonous (有毒的) to enemies, plants can fight back.

    One such plant is the Golden Wattle tree. The British scientist David Cameron has found when an animal eats the tree's leaves, and the number of poisonous chemicals becomes more in the other leaves. "It's like the injured (受伤的) leaves telling the others to fight against the enemy together," he said.

    The tree also sends messages to plants near it by giving out a special smell. Golden Wattle trees in the nearby 45 meters will get the message and produce more poison in 10 minutes. Now, if an enemy eats too many of the trees' leaves, he will die.

    Every kind of plant is good at producing special chemicals. Animals that feed on plants or grass, like rabbits, can safely eat the leaves of one tree, but they may be hurt by its neighbor.

    In this way, plants have not only developed their own way to protect themselves, but also shared it with others. So it's impossible for a single animal to damage even a small area of forest.