A snake is an elongate legless carnivorous reptile of the suborder Serpentes that can be distinguished from legless lizards by the lack of eyelids and external ears. Like all squamates, snakes are ectothermic amniote vertebrates covered in overlapping scales. Like lizards, from which they evolved, they have loosely articulated skulls, and most can dislocate their lower jaw in order to swallow prey much larger than their own head. In order to accommodate their narrow bodies, snakes’ paired organs (such as kidneys) appear one in front of the other instead of side by side, and they have only one functional lung. Some species retain a pelvic girdle with a pair of vestigial claws on either side of the cloaca.
