There are about 40,000 types of spiders in the world, living on every continent except for Antartica. Spiders are predatory eight-legged creatures, making them beneficial insects. Some spiders can be extremely dangerours to humans if bit.
Spiders are beneficial for their own pest control, eating mosquitos and other nuisance insects. They are a nuisance in many situations though due to the webs they spin near, on or in our homes. They are also a nuisance simply by their presence as a lot of people have a fear of spiders.
Spiders live in almost every habitat on earth. Outside of oceans, the highest mountain tops and the polar regions, spiders can be found everywhere. Many prefer dark and damp conditions.
Spiders all have the ability to bite with venom-injecting fangs used to kill prey. Most bites on humans do no more harm than a mosquito bite or bee sting, however some can be extremely dangerous sending many to the emergency room each year.