Rattlesnakes Rattle snakes are venomous snakes belonging to the family Crotalinae. Common rattle snakes belong to the genera Crotalus and Sistrurus. About 30 species of rattle snakes are known with many subspecies. They are viviparous and give birth straight to young ones. No egg laying was listed so far. Young ones when grown are independent and don’t need the support 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 internal 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. Arizona has the largest population of these snakes in comparison to other states. Four species have been recorded from Mississippi river and just 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 then the prey is swallowed by constriction. Venom of rattle snake can cause death within 20 seconds. After injecting venom into the body of the prey rattle snake allows the prey to operate and then follows it and when it dies it is consumed. They are known to attack at distances up to two-thirds of their body length. Many species are oviparous but they’re either viviparous or ovoviviparous. No parental care has been observed in them. They are named rattle snakes due to the existence of a characteristic structure rattle. Rattle is made up of a set of nested, hollow beads that are actually epidermal scales present in the tip of the tail. Every time a new rattle segment is added to the tip of tail as the snake sheds its skin. Skin may be shed several times in a year depending upon the food supply and growth speed. The young ones lack operational rattles but after they shed their skin it becomes practical. Rattle produces a rattling sound. They’re known to absorb great deal of water from wet weather and no sound is produced. Different species differ in their land, markings and identification. It usually avoids encountering with people. But if triggered it bites them. Hikers are constantly advised to wear boots and pants while exploring the regions where rattle snakes are expected to exist. They have functional fangs for injecting venom into victim’s body. They can also regulate the quantity of venom injected. Young ones are also dangerous. Venom is haemotoxic capable of destroying cells, degenerating organs and causing coagulopathy. It’s been observed that around 7,000-8,000 people are bitten by poisonous snakes in United States every year of which rattle snakes account for 72%. Anti-venom can be used to experience the venom injected by these snakes. They’re a popular delicacy in southeastern and southwestern America.