4.9 
Yucky Spaces
Exposed earth itself contributes a lot of water into the air, so when there is also standing water, the relative humidity will sky rocket. Because a house is made from organic materials this is not a good situation as mold and fungus will start to grow.
Icky Spaces
Spiders prey on other insects, so with one infestation another 8 legged kind will likely follow...
Cleanspace!
As insects and rodents search for food and warmth during the winter months, having a clean space liner sealing all and any cracks and holes to your crawlspace will allow you to sleep easy knowing that they have no place in your home.
