The scorpion , also known as a scorpion or alacrau , is an invertebrate animal arthropod (with legs formed by several segments) that belongs to the order Scorpiones being framed in the class of arachnids.

Scorpiones is the order of terrestrial arachnid arthropods that gathers about 2,000 type of scorpions that have length of 10cm to 12cm, elongated body and chelicerae with three articles. They are usually discreet and nocturnal animals, hiding during the day under tree trunks and barks.

The sting of the scorpion (called telson ), besides serving to grab the prey, to defend itself, and in mating, inoculates in the prey a poison . This venom contains a number of substances whose chemical composition is not well defined nevertheless contains neurotoxins , histamines , serotonins , enzymes , enzyme inhibitors, and others. It appears, according to the researchers, that neurotoxins act on nerve cells of prey, with a certain specificity, depending on the type of animal.

It is interesting to know that the poison toxicity of a scorpion can be compared to the size of its pedipalpos (the equivalent of the human arm of the scorpion); the more robust the pedipalpos , the less the scorpion uses the poison for its prey and the smaller the scorpion, the more venom of the scorpion can be lethal to its prey.

The scorpion venom of the Tityus serrulatus type , which appears to be the most toxic poison of every scorpions in South America , acts on the peripheral nervous system of humans, causing pain, pangs, increasing heart rate and lowering body temperature. These symptoms, due to their body weight, are more pronounced in children, and due to physical conditions, the elderly. All scorpions are poisonous, nevertheless only 25 type can be deadly to humans. Its sting resembles the degree of toxicity of a bee ‘s sting.
