It lives in your pillow and if you have asthma it could be your worst enemy. It is the dust mite.
The house dust mite are tiny (up to 0.3 mm) arthopods, which revel in the dust. Their numbers in a house depend not on cleanliness, but on the amount of moisture in the house. They eat the dust, which comes from our skin all the time. They leave droppings everywhere they go. Their droppings contain leftover enzymes, which the mite use to digest the skin dust. It is these enzymes that cause asthma and other allergic diseases.
In fact, house dust mite and their droppings are the most prominent cause of asthma worldwide. There is ample proof that minimising mite leads to a decrease in allergic symptoms. But, in practice it is proving to be almost prohibitively difficult for most people to beat this little pest.
One way found out of the vexing problem has been the new patented bedsheet which prevents the mite from breeding in the bed or the pillow or peircing through the thickly knit fabric of the sheet.