Many people have a phobia when it comes to spiders; hairy legs, devious traps, “innocent victims”: this is the picture that they usually imagine. This unjust pattern is not justified since even the most poisonous spiders will not attack a human unless they felt threatened. All spiders need to inject venom in order to survive, it is in the nature of their species and one of the life mechanisms they have been endowed with; what really differs from one species to another and gives rise to the classification into poisonous and non-poisonous is the amount of venom and its toxicity. From the temperate to the hot climate, poisonous spiders will be a more or less big threat for humans.
Without being lethal for a human being, poisonous spiders can cause very advanced tissue damage known as necrosis. There is a whole range of symptoms, one nastier than the other that accompany the bite of a dangerous spider: digestive troubles such as nausea and vomiting, headaches and fever, not to mention the local discomfort manifested as pain and itchiness. The bite of the same poisonous spiders may trigger different reactions in separate individuals, since personal sensitivity to the toxins in the venom matters a lot.
In geographical areas where poisonous spiders are known to live, people often learn how to differentiate them from the non-toxic species that are frequently encountered around the house. Very seldom would one take a photo or a drawing of a poisonous spider and try to compare it with a specimen identified in open air.
Knowledge of the various features comes from direct contact and experience shared in the community; thus a parent will teach his or her child how to recognize and avoid poisonous spiders. A bite exposes the victim to a whole series of unpleasant symptoms that require immediate medical intervention.
Nevertheless, extreme attitudes towards poisonous spiders give rise to phobias and the urge to destroy their nests even in the wild. Keep in mind the fact that these creatures will not attack unless they feel threatened, as a human is no prey for their match. The harm the spider venom can inflict depends on the fierceness with which the spider will defend itself. Furthermore, poisonous spiders are part of balanced ecosystems where they insure a living equilibrium among other species of insects.
Without certain poisonous spiders, some insects would breed uncontrollably and would require permanent human intervention to reduce their numbers.