Old attic insulation can cause many problems. If it gets wet, it can cause toxic moldy air that can travel throughout your home and make you or your loved ones sick. The old insulation can make a cozy little apartment for local rodents, leaving you with the gross mess they leave behind. And, finally, it can cause draftiness and high energy bills throughout your home. If you find that your A/C or heat is running all the time, this could be the culprit. For this homeowner in Herndon, VA, it was definitely time to remove and replace the attic insulation.