There are at least 50,000 species of spider in the world. Spiders have eight legs and two body sections: the thorax and the abdomen.  Spiders inject their venom through the fangs into the victim (usually an insect). Most spiders are not dangerous to humans because their fangs are either too short or too fragile to pierce human skin. Most spiders do not cause serious bites in humans. Most spider bites are mild and result in small puncture wounds, redness, itching, swelling and pain that lasts a couple of days. Bite marks from most spiders are usually too small to be seen. Spiders rarely bite more than once. Tarantulas are large, hairy spiders with sharp bristles. The hairs can shed easily and can cause skin or eye irritation. Because of its large size, bites from a tarantula can be very painful. First aid for spider bites Wash the bite site with soap and water. Wrap a few ice cubes in a towel and apply on the area for 10-15 minutes to stop the pain and swelling. To prevent frostbite, do not apply ice directly on the sting area. If there is eye irritation, rinse the eye under gently running cool water for at least 15 minutes. Prevent run-off water from entering the unaffected eye.