I don't know much about snakes (I study the ocean) but here's some information I found for you. I bet that if you went to your local zoo or natural history museum, the people who work there would be able to demonstrate these things for you!

How do snakes inject venom into their victims?
One type of venomous snake (not all snakes produce venom) is the rattlesnake, a snake common to California. Rattlesnakes have fangs that lie flat along the roof of their mouth and actually fold down when they want to bite something. Behind the fangs (one on each side of the mouth) lie venom sacs that store the poison. When the fangs puncture an animal or person muscles in the face squeeze against the sacs, pushing the venom out of the sacs, through the fangs (they are hollow) and into the wound. For a picture of snake fangs, check out this web site on Rattlesnakes:
http://www.nhusd.k12.ca.us/ALVE/NativeAmerhome.html/Navajo.html/Navajo_Anima
ls.html/rattlesnake.html

How do snakes slither?
According to Brad Moon at the University of Michigan, snakes have five methods of locomotion. In all but one of these methods, snakes use strong muscles that run from head to tail along the sides of their body (lateral muscles). By contracting the muscles on one side of its body and stretching them on the other side, a snake can make its body curve in an S-shape. By pushing this curve against the ground, the snake can push itself forward. If the snake is moving on sand, however, this doesn't work and so snakes have to use a "side-winding" technique: they still make S-curves, but instead of pushing against the ground, the curves stay flat against the sand on one side of the snake and on the other side they lift off the sand and move forward. This moves the snake in a sideways direction. The last method of locomotion, the one that does not involve using the side muscles, is similar to how an inchworm moves. The front part of the body stays in contact with the ground and the rear end moves forward, causing the snake's back to arch. Then the front part lifts off the ground and stretches forward while the rear part stays put. This movement is preferred by large, heavy snakes, such as boas.

How do snakes keep from biting themselves?
As mentioned earlier, Rattlesnakes do not bite themselves when they close their mouth because their fangs fold down and lie flat against the roof out their mouth.


More detailed information about snake locomotion: