A、By their sense of sight. B、By their sense of hearing. C、By their sense of touch. D、By their sense of smell. D

Most ants are hard workers and often work from six o’clock in the morning until ten o’clock at night. The work is divided among the worker ants so that each one has a certain amount to do. We do not know how they decide what each one is to do, for they do not talk, some people think ants follow each other by their sense of smell. Ants often live to be one year old, and some have been known to live six or seven years. One way they get their food is from plant lice, which we might call their cows. The ants milk these "cows" by tapping the lice gently until a drop of honey comes out. Then they eat the honey. Ants take very good care of these plant lice and often build a covering over them so that they will be protected from the rain.