摘要
Even though many schools are out for the summer,most fish tend to stick together and swim in schools wherever they may be.When fish stay together for social reasons,biologists say they are“shoaling(群聚)”.If they also swim together in the same direction,they are“schooling”.So why do fish shoal and school together?The main reason appears to be that there’s safety in numbers.Staying together in schools helps to protect fish from their enemies.While a predator(掠夺者)might easily catch a fish by itself,it’s much harder for a predator to single out a victim if a fish is surrounded by hundreds of its closest friends.
