Spiders are believed to have spent 300 million years sharpening their skills as well as staying alive and giving rise to new generations of spiderlings. They have emerged some 100 million years ago, an era predating back-boned animals.
Spiders are classed with arthropods. Almost all the species in arthropods have joint legs and their external armor is hard and tough. Perhaps you'd be wondering as to how long do spiders live. Stick to the end and you'll know what you want! Spiders alone claim the order Araneae. Currently, scientists have successfully found 38,000 species of spiders all around the world. It is still considered to be the tip of an iceberg since equal numbers of spiders are believed as undiscovered.
The widespread presence of spiders makes them a popular species; they are found in houses, gardens, forests, other terrestrial habitats, and caves around the world. The South American Tarantulas, also called a bird-eating spider, is the largest spider species averaging 10 cm in length, with a leg span of up to 27 cm. The smallest spiders rarely exceed one millimeter in length when adult. However, all these species are predators but not all of them use venom to kill their prey.