We know that high humidity might not seem like the most serious problem in your home, but you should be worried if it stays that way for a long time. Humidity and dampness can damage your home in a lot of different ways. Some of these problems will last longer than others. Most of the time, high humidity for a long time causes wood to rot and mold to grow. Small animals like rodents and bugs like to live in dark, damp places, so your crawl space is the best place for them to live.