Dustmites don't survive when the humidity is:

A.  Below 70 percent

B.  Below 55 percent

C.  Below 40 percent

D.  Below 25 percent
 

The correct answer is (C) – Below 40 percent.  The food consumption and development of the dustmites increases with higher relative humidities (70 to 80%) and common indoor temperatures (75 to 80 degrees Fahrenheit).  Dust mites and their droppings are known allergens. It is a protein in the mites and their feces to which people develop an allergic response.