Baby Rattlesnakes are born(yes, Rattlesnakes give birth to live young, rather than laying eggs)with one small rattle segment, called a "button". Each time they shed their skin, they get another segment. It usually takes at least 3-4 segments to be able to make any noise, though. Keep in mind that nearly ALL snakes, including harmless, non-venomous ones, will shake their tails if they feel threatened, and in dry leaves or grass or on paper, it can sound somewhat like a rattle.
