Dogs belong to the canine.

　　When a dog follows its nose,its actually being led by thee key senses.Sight:a glimpse of the enemy saves them barking up the wrong tree.Sound:a bark can be a fierce threat,but its also how canines make their long distance calls.Smell:this tells a dog more than all the other senses put together.

　　Inside its nose are around two hundred million smell sensitive cells,forty times more than in humans.Through them the dogs brain can pick up signals from one molecule of scent in a million.It gives the dog:a completely different picture of the world,based on what it smells,rather than what it sees.

　　Flowers are irrelevant to a dog.So their scent is meaningless.But food is a serious matter.What to us is an empty plate,is covered with the smell of chicken to a hungry dog.

　　狗屬于犬科勸物.

　　當(dāng)狗用鼻子嗅著前行時(shí),實(shí)際上有三種感覺在起作用：視覺,瞥一眼就知道敵人在哪兒；聽覺,犬吠有一種兇猛的威懾力,這也是犬科動(dòng)物閩相互嗅尋的方式；嗅覺,能給狗提供的信息比其他感覺總和還多.

　　狗的鼻孔大約有2億左右的嗅覺細(xì)胞——比人多40倍.通過這些細(xì)胞,它的大腦能從100萬個(gè)氣體分子中篩選出1個(gè).根據(jù)所聞而不是所見的東西,展現(xiàn)給狗的是一個(gè)完全不同的畫面.

　　花對狗來講無足輕重,所以花香對狗無關(guān)緊要.可食物是件大事,對我們來說是一個(gè)空盤子,可對一只饑腸轆轆的`狗來說卻散發(fā)著雞肉的香味.