Have you added insulation to your home or installed new air tight windows recently? If you have you want to make sure that your attic is vented to industry standards.
Did you know that in the 1970's a typical home had 18 full air exchanges of fresh air into the home. This air would enter through cracks in the window, doors, and poor insulation. Today a brand new home has approximately 3.
What does this have to do with your attic? The air and moisture that was travelling through your window cracks can be sealed into the house after additional insulation is added or new windows are installed. This warm air and moisture will travel up through the house and roof. If the attic is improperly vented, the moisture can condense and freeze providing the moisture necessary for mold to grow.