The rattlesnake's rattle gets bigger every time it sheds its skin. A rattlesnake sheds its skin two to four times a year depending on its age and rate of growth. The rattle is actually modified scales and is made up of interlocking segments which click together when the snake vibrates its tail. The snake can vibrate its tail so rapidly that clicks of the rattle segments blur into a loud buzz. Rattlesnakes and alive.
Some animals have eggs that develop inside the body of the mother before they are born.
They are called ovoviviparous. Inside the egg, the developing rattlesnake is nourished by the yolk of the egg. Animals that lay eggs that develop outside of the mother's body, including most reptiles, are oviparous.