While we're on the topic of things that shouldn't stay in your house for years, here's an apparently true bit from snopes.com:
A single guy lived in this townhouse for 8 years in Ogden, Utah. They thought he was the best renter because he never called or complained and was never late on a payment. These pictures don't even come close to what it looked like. Century 21 had already moved some of the cans out and had caved in tunnels he had made to get to the bedroom, bathroom and kitchen.