In a fury of anger, Athena destroyed Arachne's weaving and beat her about the head. In utter disgrace, Arachne hanged herself. A regretful Athena changed Arachne into a spider so that she could weave forever. While they are certainly not going to win any popularity contests, spiders' insect-eating habits are extremely helpful to humans. If every spider ate just one a day for a year, those insects, piled in one spot, would weigh as much as 50 million people.
Spiders are, by far, the most important predator of insects in the world.