Many people fear spiders. In fact, a fear of spiders has its own name: Arachnophobia! Most spiders, however, are totally harmless to humans and are actually beneficial because they eat insect pests. Even the largest tarantula in existence, the Goliath Bird-eating Tarantula, is harmless to humans. A tarantula bite is said to be about as painful as a bee sting. Some spiders, however, such as the Black Widow Spider, are dangerous to humans. Bites from these spiders usually require immediate medical attention.