Snakes – Some Facts

• The largest snakes in the world are members of the family Boidae, which includes the boa and the python. Some members of this family never attain a length of more than 0.6 m (2 ft), but the largest may grow to more than 9 m (30 ft).
• Sea snakes have no gills and must rise to the surface for air, but they can remain underwater for several hours, obtaining dissolved oxygen from water that they swallow and eject.
• Approximately 2500 different species of snakes are known. Approximately 20 % of the total number of the snake species are poisonous.
• The skin and outer covering of the horny scales are shed periodically and usually in one piece, including the hard, transparent covering of the eye known as the spectacle (snakes lack movable eyelids, and the spectacle protects the constantly open eyes). The frequency of shedding varies with different species , according to the size and age of the individual. Young, rapidly growing snakes shed their skins more frequently than the slow-growing adults. In some species the skin is shed about every 20 days; in others, only once a year.
• The big pythons can eat animals that weigh up to about 68 kg (150 lb), but swallowing such a meal is a difficult process.
• The snake must bite to inject its venom; no snake has a stinger in its tail.
• Three species of snake can spit or eject the venom in a fine spray, which is aimed at the eyes of an enemy and projected for distances up to 2.4 m (8 ft). If the venom gets into the eyes, it may cause blindness. The spitting is used only in defense and never to obtain food.
• Vision is well developed in most snakes, but many burrowing snakes are virtually blind.
• Snakes have a strong sense of smell, which is relied on to a large extent in hunting food. Snakes find their prey by sight and scent, and sometimes temperature. Except for burrowing species, snakes have excellent short-range vision. Their sense of smell is extraordinary, thanks to a harmless, constantly flicking forked tongue that carries scent particles to a specialized sensory organ (‘Jacobson’s organ’) on the roof of the mouth.
• Snakes are deaf to airborne sounds. The Cobra does not hear, as it is believed, the snake-charmer’s flute. They can, however, feel vibrations through the ground or whatever they are resting on.
• Snakes move slower than an adult human can run; the fastest recorded speed achieved by any snake is about 13 km/hr (8 mph), but few can go that fast.
• Depending on the species, snakes may be egg-layers or give birth to live young. They generally mate in the spring, shortly after leaving whatever hollow, burrow or rock crevice has sheltered them through winter hibernation. Egg-layers usually deposit groups of eggs in dirt, beneath stones or logs, or in piles of decaying wood or vegetation during late spring or early summer. Most snakes hatch or are born in late summer. Whether deposited as eggs or dropped as fully formed miniature adults, snakes are on their own from the start. Snakes do not take any responsibility for the care and protection of their young. Most snakes mature at one or two years of age, and individuals may live up to twenty years in the wild.
• The greatest age known for any snake is just under 30 years, attained by both the anaconda and the black-lipped cobra.
• Effects of the bites of Black and Green Mamba –
  Black and green mambas both produce neurotoxins, which is why they kill so fast. Black mamba is more venomous. Neurotoxin inhibitors and antivenin are generally made from the venom of the same snake, but it is likely that antivenin from one would be at least partially effective against the other. Because these are two different snakes  their venom has to be different and thus the antivenin from one may not act for the other.
• Snakes do not leap or jump into the air. Instead, those that do strike out coil themselves enough to get a push or strong outward movement designed to snatch prey or inject venom. Most snakes can only strike about one half their total body length. They do not actually leave the ground. They are capable of striking upward or outward at approximate one half length level.