Rattle snakes are poisonous snakes belonging to the family Crotalinae. About 30 species of rattle snakes are known with many subspecies. They are viviparous and give birth directly to young ones. No egg laying has been recorded so far. Young ones when grown are independent and do not need the help of mom for carrying out their regular activities. So, the mother leaves the young soon after their arrival. They aren’t deaf. They have well developed inner ears similar to that of other reptiles. External ears are absent. Sound travels towards internal ears through the vibrations picked up by body organs.
They are natives of America. Vast majority of the species have been recorded from Southwest America and Mexico. Arizona has the largest population of these snakes in comparison to other states. Four species have been recorded from Mississippi river and only 2 from South America. They prey upon mice, rats, small birds and other smaller animals. They paralyze or kill the victim by their venom and the victim is swallowed by constriction. Venom of rattle snake can lead to death within 20 seconds. After injecting venom into the body of the prey rattle snake allows the prey to run and then follows it and when it dies it’s consumed. They are known to strike at distances up to two-thirds of the body length.
Many species are oviparous however they are either viviparous or ovoviviparous. No parental care was observed in them. They’re named rattle snakes because of the existence of a feature structure rattle. Rattle is composed of a series of nested, hollow beads that are actually epidermal scales present in the tip of the tail. Skin may be shed many times in a year depending upon the food supply and growth speed. The young ones lack functional rattles but once they shed their skin it becomes functional. Rattle generates a rattling sound. They’re known to absorb great deal of water from wet weather and no sound is generated.
Different species differ in their territory, identification and markers. It usually avoids encountering with humans. But if provoked it bites them. Hikers are constantly advised to wear boots and pants while exploring the areas where rattle snakes are expected to exist. They can also regulate the quantity of venom injected. Young ones are also dangerous. Venom is haemotoxic capable of destroying tissues, degenerating organs and causing coagulopathy. It has been observed that approximately 7,000-8,000 people are bitten by poisonous snakes in United States every year of that rattle snakes account for 72%. The tropical species contain neurotoxic venom which affects the nervous system. Anti-venom may be used to encounter the venom injected with these snakes.
They are a popular delicacy in southeastern and southwestern America. Killing of these snakes is strongly prohibited and if practiced the government punishes the culprit.