I learned something while reading about vitamin C and sleep:

Untidy Beds May Keep Us Healthy, BBC News, January 2005

Researcher Dr Stephen Pretlove said: “We know that mites can only survive by taking in water from the atmosphere using small glands on the outside of their body.

“Something as simple as leaving a bed unmade during the day can remove moisture from the sheets and mattress so the mites will dehydrate and eventually die.”