Snakes

Snakes are a diverse group of elongated, legless reptiles in the suborder Serpentes. They occupy a wide range of environments worldwide, from forests and deserts to oceans and cities, with more than 3,000 described species. Snakes are ectothermic and regulate their body temperature through external heat sources. Their bodies are covered in scales, and their skulls are highly kinetic, enabling them to swallow prey much larger than their heads. Their jaws and ligaments can stretch to accommodate large meals.

Anatomy and senses vary among species. Most snakes have a pair of lungs, though in many species the left lung is reduced or absent. They breathe through the trachea and use a forked tongue to collect chemical cues, which are analyzed by the Jacobson's organ. Some snakes, notably pit vipers, possess infrared-sensing pit organs that help locate warm prey. Vision ranges from relatively acute in some species to poor in others.

Diet consists mainly of small vertebrates, eggs, or invertebrates; some specialize in fish, amphibians, or rodents. Venomous snakes in the families Elapidae and Viperidae immobilize prey with toxins delivered by fangs. Non-venomous snakes kill mostly by constriction or by swallowing prey alive. Constrictors include boas and pythons. Reproduction modes vary: many snakes lay eggs (oviparous), while others give birth to live young (viviparous or ovoviviparous).

Snakes are important predators that help control pest populations and contribute to ecosystems. They can be prey for birds, mammals, and larger reptiles. Humans may fear or kill snakes, contributing to declines in some species. Threats include habitat loss, pollution, and collection for trade. Conservation efforts focus on habitat protection, responsible handling, and public education.