Any "8 wheelers" with jointed legs wandering about planet earth.

Arachnology is the scientific study of spiders and their relatives including: scorpions, pseudoscorpions, harvestmen, and mites & ticks collectively called arachnids. About 40,000 spider species have been described, but ±200,000 species are as yet undescribed.

Spiders may be generally classified according to their various lifestyles:
1. Web-bound spiders.
2. Ground-living spiders.
3. Plant-living spiders.