Haunting spiders are normally only annoying. They develop a passionate desire to wrap one person in webs. They wait till they sleep and begin to work. Usually the victim wakes up to just a thin webbing and the feeling of scuttling legs. However, things can go differently if the victim is otherwise detained say by an accident. Sometime later police might find a rather odd, morbid silk package. No spider in sight as it seeks another to devote itself to.
This was something you needed to know.