The Gabon Viper is a snake that grows to two metres in length．It is black all over and as thick as a strong man’s arm．When angry, it barks like a dog and spits poison．It is one of nature’s most dangerous gifts to the world．Most people would prefer nature to keep gifts like that to itself．

　　Others think differently．They think that Gabon Vipers, along with other poisonous snakes, spiders and reptiles are perfect animal friends for their children．They believe that the neighbors will be envied if they keep a lion in the backyard．And they believe that no home is complete without a monkey or a parrot in a cage．That is why the trade in unusual pets is now worth over US ＄10 billion per year in spite of being illegal in most countries．

　　The serious effect of the trade is the damage it does to the natural environment．Hunters catch young parrots by cutting down the trees which the birds use to make nests in．Baby monkeys always stay close to their mothers．So the hunters simply shoot the mothers．

　　These facts are now well known, but the trade continues．It seems that the strong desire to keep pets has deep roots in the human mind．Some psychologists say that it is a way for people to get closer to nature．People keep cats and dogs as a kind of historical echo(仿效)of the days when dogs were used to control sheep and cats were kept in the home to hunt mice and rats．As technology moves society further away from the natural world, the desire to keep in touch with it grows stronger．Dogs and cats become boring．Only snakes, bears, lions and other dangerous creatures satisfy some people’s desire to get personal control over nature．

　　This is why there are now more tigers kept as pets in the United States than there are living naturally in the world．One result of this is an increase in attacks on humans．According to a report, there is more chance of a child being killed by a Bengal Tiger in Texas than there is in Bengal．

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