How do king cobras use venom?

Answer 1

It depends on the kind of snake.

For a cobra a muscle surrounds their venom glands so that when the snake bites, the muscle presses on the glands which forces the venom down the fang and out the tip.

I'd assume it's similar for all snakes.

Answer 2

The cobra can inject venom through its hollow fangs when it bites/strikes you (like a hypodermic syringe) and it can also squirt its venom through the air into the eyes of opponents when threatened.

Answer 3

they spit it