Rebecca writes from Lebanon, Pennsylvania: "I purchased my home a year ago. The previous owners had multiple cats in the unfinished basement and they were not litter box trained. The basement smelled HORRIBLE! Though I scrubbed the walls and floors, the basement still has an odor. Could the odor from the previous owner's cats be in the insulation in my unfinished ceiling? Do I need to replace my insulation?"

Answer: Ouch! I hate it when my feline friends make a mess. In their defense, I must say that we cats really aren't "trained" to use a litter box but gravitate to them naturally if they are relatively clean. Therein lays the problem in some multiple-cat situations. And if we are upset about something, we can forget our instincts.

Getting back to your question, in my humble opinion the insulation could very well have been contaminated by the cats' odor. I recommend replacement. However, don't count on that to entirely solve the problem as the ceiling joists and other materials in the basement could have absorbed some of the moisture in the air. Good luck.