According to statistics, there are about 4 thousand species of snakes in the world, about 10% of them are venomous. Every year in the world about 40 thousand people die from the bites of poisonous snakes. A high mortality rate from encounters with these creatures is recorded in Brazil and India. In the United States, up to 15 people per year die from the bites of such snakes. Isolated cases of death from poisonous snakes have been recorded in Europe.
First of all, it should be noted that the bite of a poisonous snake does not always lead to poisoning of the body with poison. For example, vipers do not secrete their venom in almost 25% of bites, and cobras in about 50% of cases. But if snake venom, nevertheless, was injected into the blood of a person, then it can immediately have a harmful effect, indirectly or directly affecting all systems of his vital organs. Attention! Not always snake venom can be dangerous to humans! Some types of poison do not act on a person at all, and some will be fatal within a few seconds.
There are several ways to identify a venomous snake, but you should never rely on them completely and completely! If a snake bite has taken place, then you need to urgently take all the necessary measures to provide first aid. So, you can recognize a poisonous snake by the following signs.
First, most venomous snakes have a brightly colored body. As a rule, harmless snakes are painted in the same color and may have one or more longitudinal stripes from head to tail. Poisonous snakes can have various patterns in the form of diamonds, spots, transverse tiger stripes, some kind of patterns (for example, "glasses" on the hood of a cobra). Some poisonous snakes have bright specks, circles, irregular colored blocks on their bodies. There are also two-colored poisonous snakes: the first half of their body is painted in one color, and the second in another.
Secondly, there is an opinion that a poisonous snake can be distinguished from a non-venomous one by the shape of its head. Allegedly, in the first it has a spear-like shape, and in the second it is more round. However, this rule is not always confirmed. Some zoologists argue that the heads of poisonous snakes do not always have a spear-shaped or triangular head. Therefore, it is dangerous to rely only on this sign! However, according to statistics, many (but not all) poisonous snakes have their heads in the shape of a spear (triangle).
Thirdly, poisonous snakes have a small dimple between the eyes and nostrils - a kind of depression. These are heat-sensitive channels. There is an opinion that the pupils of non-venomous snakes are rounded, while those of poisonous ones are elliptical. This, of course, is true, but not fully. For example, cobras and boomslangs have round pupils, but these snakes are some of the most venomous in the world.
In conclusion, it is worth noting that there is simply no single characteristic feature that would distinguish venomous snakes from non-venomous ones! The only exception can be the presence or absence of poisonous sickle teeth and glands. But the whole difficulty lies in the fact that these organs cannot be found in a living snake without the potential risk to its life. In this regard, the only reliable way to recognize poisonous snakes is to get acquainted with the venomous and non-venomous snakes of your region through scientific literature, medical sources, and the Internet.