Many animals do strange things before an earthquake.This news may be important. Earthquakes can kill people and knock down houses.Animals may help to save lives. Some animals make a lot of noise before an earthquake.Farmers know about this.Dogs that are usually quiet start to bark.Horses on farms run around in circles.Mice leave their holes and run away.Cows give less milk. In a town in Italy, cats raced down the street in a group.That happened only a few hours before an earthquake.In San Francisco.a man kept tiny pet frogs.One Sunday, the frogs jumped around more than ever.They made loud noise.That night, an earthquake struck the city.People want to know when an earthquake is coming.Then they could get away safely.Right now, there is no sure way to know ahead of time.Maybe the best way is to watch the animals. This story is mostly about   _  .
how animals act before an earthquake how an earthquake starts how mice leave their homes when an earthquake begins