Their tongue and the Jacobson's organ.
Jacobson's organ
No, venomous snakes do not track their prey by smelling the venom they inject. Snakes use their sense of smell to locate prey, and once they bite and inject venom, the venom works to immobilize or kill the prey. Venom can also aid in digestion once the prey is consumed.
Rattle snakes are their prey.
in the UK it is illegal to feed snakes live prey but people do !! if you have a larger snake and do feed it live prey some will constrict until the prey is dead but other will eat it alive and it will still be chirping or making a noise as it passes down the snakes body until it suffocates !you can view snakes eating live prey (rabbits ,birds ,chickens) on youtube
snakes have an internal part called Jacobson's organ that helps in smelling their prey.
Snakes have special organs (pit organ) between their eyes and nose that can sensor infrared's radiation. With this organ it enables it to detect animals that have heat trapped in them (example: mice, birds)
It's a 'sensory organ'. It basically takes the form of two 'pockets' in the roof of the snakes mouth. When the snake flicks out its tongue, microscopic scent particles stick to it. Withdrawing the tongue back into its mouth, the tips are inserted into the Jacobson's organ, and the snake's brain decodes the information.
The Jacobson's organ is one that helps snakes smell and sense their prey. It compares and contrasts odors in the snake's habitat and allows the snake to modify its behavior as necessary.
To find food, the snake has to find it. They use their Jacobson's organ(an internal organ that allows snakes to locate their food by "smelling" it) or their "belly" scales to pinpoint their meal using the prey's vibrations(movements). Once the prey is found, the snake forms a "S" and strikes its meal and injects venom; this making the small animal more managable for the snake.
they prey for lots of snakes like rattle snakes
cats, snakes, and birds of prey
Birds of Prey, other snakes.