CONTENTS Deadly Spiders Silk Orb Webs Tunnels Trapdoors Venom Hunting Th rowing Spitting Fishing Camoufl age Mimicry Reproduction Spiders People Spiders Th eir Enemies Th e Other Arachnids Six Spider Facts Glossary Index 6 8 10 12 14 16 18 20 22 24 26 28 30 31 32
DEADLY SPIDERS For many of us spiders are fearsome creatures But they’re also fascinating They’ve lived on Earth for more than 300 million years and have evolved to live in almost every dryland habitat from deep caves to deserts to rain forests Many seem quite at home in our houses too There are more than fifty thousand species of all shapes and sizes found worldwide except Antarctica Spiders are not related to insects They have eight not six legs their body is in two not three parts and they don’t have antennae Like insects however spiders are arthropods They have an exoskeleton outer armor that must be molted regularly as the young spider grows to adulthood You can sometimes find the empty molts in their webs All spiders make silk a strong thread that is spun from the spinnerets tiny nozzles at the tip of the abdomen Most spider species have eight eyes but some have six four or even just two 6 A spider’s body has two main parts the cephalothorax supporting the eyes mouthparts and legs and the abdomen containing most of the internal organs Leg IV Spinners Leg III Abdomen Femur Patella Tibia Cephalothorax Metatarsus Tarsus Claw Eyes Leg II Chelicera Palp Leg I There are four pairs of legs numbered I to IV front to back
Spiders are predators Some catch their prey in webs some ambush it and still others chase it Spiders can’t eat solid food so most spiders use venom poison to kill or paralyze their prey and turn its insides into a kind of gut soup In some species the venom is so strong it can harm or even kill humans but the majority of spiders cannot hurt us They even help us by killing pests It’s been estimated that the prey eaten each year by all spiders weighs more than the entire human race
