The biggest spider in the world is Goliath Bird-eater (Theraphosa blondi), from the tarantula group. It lives in the rain forests of South America.
It has a leg span up to 25 cm, and can weigh over 170 grams. Females have life span of 6 to 14 years and males live from 3 to 6 years. This discrepancy is due to the fact that female eats a male after copulation.
They live underground in the holes or burrows they’ve dug out themselves or use abandoned burrows left by some other animal. Goliath Bird-eater got its name when a Victorian explorer supposedly saw it eating a hummingbird. Goliath tarantulas don’t usually prey on birds unless they have to.
Their diet consists of insects, myriapodes and because of their size they can sometimes attack a rodent, lizard or even a venomous snake. They attack with their fangs, injecting prey with poison which turns prey’s soft tissue into fluid. Since spiders don’t have any teeth to eat with, they suck out the dissolved tissue.
They are usually harmless to humans, and some Amazonian tribes see them as “food with legs” because they are quite easy to catch and are very nutritious. Natives even use spider fangs as toothpick after they have finished eating the spider. They have a way to defend themselves, though.
To protect themselves they rub their abdomen with hind legs. This causes tiny hairs from the abdomen to be released in the air. These tiny hairs are very irritating for the eyes and mucus membranes. They can even be harmful to humans, so think twice before you go looking for your own “food on legs”.
There are certain reports of Giant huntsman spider (Heteropoda maxima) according to which it is even bigger, but there are not enough relevant data to confirm this fact. However there are speculations that spiders belonging to this species have the leg span of over 30 cm!