Answer the following questions based on the text!

    Last dry season I spent days in the garden watching thousand of ants crawling up the trunk of my prize peach tree. The tree has grown against a warm wall on a sheltered side of the house. I am especially proud of it, not only because it has survived several draughts, but because it occasionally produced luscious peaches. During the dry season, I noticed that the leaves of the tree were beginning to wither. Cluster of tiny insects called aphides were to be found on the underside of the leaves. They were visited by a large colony of ants which obtained a sort of honey from them. I immediately embarked on an experiment which even thought failed to get rid of the ants, kept me fascinated for twenty-four hours. I bound the base of the tree with sticky tape, making it impossible for the ants to reach the aphides. The tape was so sticky that they did not dare to cross it. For a long time, I watched them scurrying around the based of the tree in bewilderment. I even went out at midnight with a torch and noted with satisfaction (and surprise) that the ants were still swarning around the sticky tape without being able to do anything about. I got up early next morning hoping to find that the ants had given up in despair. Instead, l saw that they had discovered a new route. They were climbing up the wall of the house and then on to the leaves of the tree. I realized sadly that I had been defeated by their ingenuity. The ants had been quick to find an answer to my thoroughtly unscientific methods.

 Why did the ants visit the tree?