If you've ever wanted an excuse not to make your bed, there's a scientific reason to avoid the daily chore. When you retire to your mattress for much-needed rest, you're getting in bed with millions of house dust mites, which are microscopic insects that feed off flakes of human skin.

What house dust mites do to your bed.

Because your sheets are full of dead skin flakes, the bed is a perfect place for house mites to colonize—and they even make your mattress heavier overtime.

Everyone moves around and sweats while they sleep. Some people can sweat out a liter of water per night, and the average person switches positions a dozen times while sleeping. All of this activity enables house dust mites to mate and reproduce, and when you wake up in the morning and make your bed, you trap all the sweat and mites inside your bed.

These mites can also cause irritation. When house dust mites excrete waste, they release allergens that are known for causing asthma and allergies.

"Their droppings are composed of protein compounds," Global Health Center reports. "When we breathe in these protein substances, or when they come into contact with our skin, our body tries to protect us by producing antibodies. In turn, our antibodies release histamine which is a chemical that causes the typical swelling and red color associated with allergies."

Why not making your bed can be a good idea.

If you don't make your bed, you expose the mites, dead skin, and sweat to the air, making it harder for mites to survive, according to a 2005 study from Kingston University. Researcher Dr. Stephen Pretlove told BBC at the time that an unmade bed creates a dry environment for house mites that depend on dampness and wetness to live.

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

Experts say leaving your bed unmade for a full day can kill many of the allergen-purveying house mites, but that doesn't mean you're totally safe. House mite excrement can linger and cause allergies.

Another way to kill dust mites is to regularly wash your sheets in warm water. Dr. Lisa Ackerley, a home hygiene expert, told MailOnline earlier this year that allergen protectors on mattresses and pillows could also help those with allergies. She also said airing out one's home could help.

"In alpine areas, people used to hang their bedding and their duvets out of the window," Dr. Ackerley said. "The cold alpine air kills the dust mites. They probably didn’t know they were doing it for that reason, but it’s a good idea."