Why be afraid of spiders?

Amblypygi are a nocturnal group of arachnids, commonly called whip spiders or tailless whip scorpions [...] Amblypygids also have spiny, raptorial pedipalps that are used for defense and to capture prey. Amblypygids possess no silk glands or venomous fangs and are harmless to humans.
Amblypygids can live around 5-10 years and are found in warm tropical and subtropical regions worldwide. They seek refuge during the day in crevices of trees, rocky outcroppings or cliff banks, underneath rocks or bark, and come out at night to be active.