how to know if a spider is poisonous or not

Spiders are very interesting insects, you have been the subject of false myths that promote the fear of people towards any arachnid. However, it is important to be cautious and to know if a spider is poisonous or not, this article is oriented to clarify this doubt.


It is not difficult to know if a spider is poisonous or not, most of them are poisonous, but there are very few poisonous spiders that are threats to human beings.

First of all you should know that if you find a spider, do not kill it, try to capture it to identify it, in the case of being poisonous you can determine what is the antidote to eliminate them

Know the habitat where you live, investigate the type of spiders that are native to the place where you live, this will help you to know if you should worry every time you see a spider.

These are some poisonous spiders that you should know:



You can find it anywhere on the planet, they have an abdomen that is 4 times bigger than its cephalothorax, it is characterized by its long legs compared to its body, although not more than 3 cm, it has small hairs and thorns in them.

Sydney spiders

sidney spider

Also known as atrax robustus, they only inhabit Australia, measuring 5 to 7 cm. They can be recognized as bluish-black, have a pair of long fangs and a hairy abdomen.


They are better known as violin spiders, they are anywhere in the world, you can identify them by having an elongated abdomen, long legs, their pedipalps.

Of the species loxosceles the lethal ones are:

loxosceles recluse
Loxosceles Recluse (7-10mm)
  • Apachea, (North American Corner Spider)
  • Laeta, (South American corner spider, is the most toxic of this group)
  • Recluse, (North African recluse spider)
    In the world there are more than 100 species of this type of spider, so it is important that you know if there are any of them where you live.

If you want to know how to eliminate spiders visit the following article:

Homemade tricks to kill spiders