Arachnophobia is the fear of arachnids. Commonly, people just simply say it is the feat of spiders. However, arachnids are a bunch of other insects aswell. This includes scorpions, harvestmen (daddy long legs, but they're not technically spiders), mites and ticks. Despite people not having a fear of arachnids, they still say they have arachnophobia to mean they're scared of spiders.