蛇(snake)
有鳞目蛇亚目中约11科爬虫类的统称，无四肢，不发声，无外耳或眼睑，只存一个功能肺和细长的身体。已知现存约2,700种，多数分布於热带。体表有鳞，视觉锐利，并一直以舌探试周围环境。虽缺乏发声构造，蛇仍可发出嘶嘶声。多数生长於陆地上，有些则为树栖或水栖，亦有些居於洞穴中。藉肌肉收缩和伸长的腹鳞帮助而运动。蛇是大胆的捕食者，70%独栖的蛇会跟踪、捕捉并消化其活生生的猎物。其颚及身体的构造能将大型猎物整个活吞下去。交配和产卵（或行卵胎生）为短暂的季节活动。约1/5的蛇类有毒，有些咬人後而使人类致死。其他种类靠缢缩身体或活吞而杀死猎物。体长范围从不及12公分至超过9公尺。蛇类终生在生长，在每一生长期蜕去外皮。各大洲皆有分布，少数种类见於岛屿或冬季较长的地区。
English version：
snake
Any member of about 11 reptile families (suborder Serpentes, order Squamata) that has no limbs, voice, external ears, or eyelids, only one functional lung, and a long, slender body. About 2,700 snake species are known to exist, most numerously in the tropics. Their skin is covered with scales. They have good eyesight, and they continually taste the surrounding air with their tongues. Though they lack any voice, they are capable of hissing. Most live on the ground, but some are arboreal or aquatic, and some are burrowers. They move by muscular contraction, aided by elongated scales on their abdomen. They are fearless predators, focusing 70% of their solitary existence on tracking, capturing, and digesting their living prey; the construction of their jaws and bodies enables them to swallow large prey whole. Mating and laying eggs or bearing live young are brief seasonal activities. About one-fifth of snake species are venomous; some can kill humans with their bite. Others kill their prey by constriction or simply ingesting. Species range from less than 5 in. (12 cm) to over 30 ft (9 m) long. Snakes grow continuously throughout their life, shedding their outgrown skin at each growth increment. They inhabit all continents, but few species are found on islands or in regions with long winters.