There are only a few species of tarantula that are usually kept in captivity as pets or for breeding purposes. While there are actually about 900 species of these types of spiders, mainly found in tropical and sub-tropical climates, such as the southern and western USA, Central and South America, Africa, Asia and Australia, they are a hardy species and have moved around the world to various warmer climates in shipping containers.

In general, tarantulas are considered large hairy spiders. They are a type of arachnids (like all spiders) and almost all of them belong to the Theraphosidae family. A few other arachnids are considered tarantulas because of their physical features, but have a different genealogy.

The two main types that are kept in captivity are the arboreal tarantulas (tree dwelling, usually from South America) and the ornamental tarantula spider (smaller variety, from India and Sri Lanka). In many places, there is a conscious ethical effort to make sure that tarantulas are not captured and taken from their natural homes and in fact these days if you want to buy a pet spider then you can do so from breeders either online, or through your local pet store.

Arboreal tarantulas.
There are a huge number of species of arboreal tarantulas. They are characterized by the fact that they live mostly above ground in trees. They have a much lighter build that consists of a thinner body and longer legs, which makes it easier for them to move about and keep their balance high up in the trees. They can climb any surface and even move about upside down, as they have special hairs on the ends of their legs that will grip any surface they are on.

There are several sub species of tarantula spider in this group that live in a variety of different locales: the Heteroscodra makes its home in high grasses, bushes and low hanging palm tree leaves; the Avicularia is native to tropical rain forests and makes its home in bromeliad type plants (such as pineapples); and the Poecilotheria likes to hide in tree hollows or other spaces that have been made by insects or birds.

Land dwelling tarantulas.
There are also a huge number of terrestrial tarantula spiders, which can dig holes in the soil to make their homes. For instance, the very popular Brachypelma boehmei (Mexican fireleg), digs burrows under thorny bushes and large rocks.

Other features.
All tarantulas are poisonous, but it is rare that their poison is fatal for humans. Their bite can be very painful and irritating though. Most of them have special hairs on their backs, which they can fire at any perceived danger and if these get lodged in your skin they can be extremely irritative. It is recommended to always wear protective eye goggles whenever you are handling tarantulas!