Horses are used in guarding herbs, carrying men in lands where there are no roads, and helping farmers work their land. Pigeons have long been used to carry messages. Wild animals from the jungles, forests and seas are very popular performers in circuses and moving pictures. People realize that, although animals may not have the same intellgence as human beings, they are smart enough to know certain things. Horses are also able to learn many things. Homes that are used for guard or police duty must learn never to be frightened of noises, traffic, and other disturbances. Racing horses are able to run much faster than other horses, but they are also quite high strong. Therefore, it is necessary for those people who train them to be very patient and understanding. Pigeons have a natural instinct to return home, even if they are very far away and the trip is hard or dangerous. Men utilize this homing instinct to send messages on small pieces of paper which are fastened to the pigeons’backs or legs. In war time, pigeons have been known to fly as fast as 75 miles an hour and to cover distances of 500 to 600 miles. These homing pigeons begin their training when they are about four weeks old. After a few weeks they can begin flying and carrying messages. If all goes well, their flying career lasts about four years. Animals can learn to do many things that, while not necessarily useful, are very amusing to watch. In circuses, animals are taught to do the tricks that are most suitable for their physical and temperamental make-up. Lions and tigers can be taught to leap and spring gracefully when told to do so, or to stay in place on command. Elephants leant to walk in line, to stand on their hind legs, to lie on their sides, and to stand on their heads. They can also learn to dance. Once a trainer had an elephant and a tiger. After many weeks of living in the same cage, the two animals became accustomed to each other. Then the tiger was taught to jump on the elephant’s back. Both animals became so interested in the act as well as the praise and food they received after the act, that they for-got they were natural enemies. Later a lion was added to the act. This also took a lot of patient training. How ever, when the three animals grew accustomed to each other they made a most successful Circus act. Race horses are hard to train because they are ______.