Baby snakes are commonly referred to as snakelets. Newly born snakes are called neolates, while newly hatched snakes are called hatchlings. A group of snakes is called a nest.
As of 2014, more than 20 families of snakes are recognized; these families include 3,400 different snake species. Snakes vary in size from the small thread snake, which is less than 4 inches long, to the reticulated python, which reaches lengths of up to 29 feet. Snakes are found on all continents except for Antarctica.
The majority of snake species are non-venomous. Venomous snakes such as cobras and vipers use their venom to kill prey instead of for self-defense, with some capable of causing death to humans. Non-venomous snakes kill their prey through constriction or by swallowing it whole.
Snakes feed on small animals such as frogs, lizards, other snakes, mice, birds, snails, insects and fish. The size of the snake determines the size of its prey; larger snakes eat larger prey. A full-grown python, for example, may eat antelope or deer.
All snakes have skin that is covered with scales. During molting, a snake's old skin is replaced with new skin. While older snakes typically shed their skin only once or twice per year, younger snakes may shed their skin four times per year.