No, snakes aren’t mammals. Snakes are reptiles, they are close relatives of lizards, turtles and crocodiles. Reptiles are an ancient class of animals that appeared at least 310 million years ago and reached its heyday in the Mesozoic era from 240 to 65 million years ago. Snakes descended from lizards about 135 million years ago and became the last of the reptile groups that appeared on Earth, but even now in nature one can find species that are in the transition from lizard to snake. Such individuals have a snake’s body, but at the same time they still have limbs.
All reptiles are “cold-blooded”. This is not a very accurate description, which in relation to them simply means that they can function normally only when the body temperature rises. Indeed, although they can not independently produce heat for their bodies, like mammals, they prefer to operate at an air temperature of about 25-30 ° C, depending on the species, and can maintain their body in a significantly stable temperature regime, moving from warm places to cold and vice versa.
In cold weather or early in the morning, they often bask in open spaces, trying to collect as much solar energy as possible, while in the heat they seek shelter under rocks or in burrows and are most active at night. During a prolonged cold snap, they can hibernate for several days, and in cold places of the globe, such as Northern Europe, for several months to survive extreme cold snap.
Snakes differ from lizards in a number of parameters. Snakes do not have limbs, whereas most lizards have them. Those few species of lizards that do not have limbs, such as the spindle and the armored spindle, have eyelids. Serpents do not have eyelids, once they evolved into transparent films covering their eyes. Snakes also have one set of specialized abdominal scales running along the body, whereas lizards have several rows of scales, differently oriented on the ventral side of the body.