With the help of its forked tongue, a snake can detect if its prey has stopped and has crouched down on the ground, motionless, half a meter in front of it. Despite the pitch dark, its heat detection system accurately locates its prey. First it creeps silently forward until it reaches the attack distance, then rears back its head and leaps onto its victim like a spring. By this time it has already sunk its fangs, in its jaw that can open up to 180 degrees, into its prey. All this takes place at a speed equivalent to a car reaching 90 km/hour (55 mile/hour) in half a second.
In incapacitating its prey, the snake's most important weapon are its poison fangs, which can be as long as 4 cm (1.5 inches). These are hollow, connected to a venom gland whose muscles contract when the snake bites to inject the venom under high pressure—from the fang's canal to under the skin of the victim. Snake venom either paralyses the victim's central nervous system, or else kills it by congealing its blood.
An experiment determined that the snake identifies whether a source of heat represents genuine prey by its heat sensors and forked tongue working together. In total darkness, a hot sandbag and a dead animal were left out in front of a snake, who first moved towards the sandbag, but did not try to swallow it. Although the dead animal emitted no heat, the snake examined it with its tongue when it came across it, and then began eating it. These two sensory systems have been created with features that complement one another. Were that not so, the snake would waste its time in attacking every heat source it encountered.
It is astonishingly apt that the snakes' night vision system should be able to establish another animal's location accurately and that it should have the equipment necessary to kill it with venom.
Of course, those who deny the existence of God can't explain how the snake has a poison system in its jaw that's most complex and specially planned. For the system to function at all, the fangs first need to be hollow, then the venom glands connected to them, and the venom itself must be powerful enough to quickly paralyze its prey.
Furthermore, the system must operate by reflex the moment the snake bites its prey. The absence of just one of these many components will mean that the whole system cannot function. This could result in the snake falling prey to the very animal it had selected as prey.
Another detail needing additional consideration is the way the venom the snake's body contains doesn't harm the snake itself. The glands that store the venom need to have a protective feature to keep it from spreading through the body, killing the snake. The venom system, which exists as a composite whole, clearly cannot have arisen in stages via an imaginary process of "evolution."
Just thinking about the venom system is sufficient to reveal the laughable nature of evolutionists’ claims of "chance emergence," because as you can see from the examples just cited, everything in the snake's bodily systems is exceedingly complex and inter-related. Heat sensors or poison fangs evidently cannot appear one day by some mutation. In a crude description of the stages that would have to take place, the fangs would need to appear first, before the hollow passages inside them. Then the snake's body would have to "learn" what formula of venom affects warm-blooded animals; and then the snake would have to produce venom inside its own body. Everything, right down to the smallest details, is flawlessly arranged. God, the Omnipotent, created rattlers with their perfect scent detection abilities, poison systems and all their other attributes. In the Qur'an, those who refuse to have faith are described by God as cruel and He goes on to reveal:
Who could do greater wrong than someone who is reminded of the signs of his Lord and then turns away from them, forgetting all that he has done before? We have placed covers on their hearts, preventing them from understanding it, and heaviness in their ears. Though you call them to guidance, they will nonetheless never be guided. (Surat al-Kahf: 57)
