Spiders have 8 legs that are jointed and some have fangs that inject venom to their prey. There are approximately 40,000 species of spiders. They are air breathing and they can live in any habitat with the exception of air and sea colonization. A vegetarian species was discovered in 2008 but all others are known predators. They feed upon small insects (flies etc.) They spin a web to catch their victims and the female weave silk egg cases that may contain hundreds of eggs.