I just saw this sad article about a woman in Canada who bought a million dollar home. She thought that having an architect and engineer walk through the home would be enough to verify that it was safe for habitation, so she didn't get a home inspection. After closing, she discovered that the walls were totally and completely infested with mice. Yuck!
Worse still... the damage from their droppings and urine is so severe that the house has to be gutted.
Enough said, right? Here's a link to the article - don't be shy if I can help you with anything!