Typical wet and dirty crawlspace
Unfortunately this picture is what it looks like under a lot of homes in the Delmarva area. Lots of falling and hanging insulation, wet dirt, musty smells, and high humidity.
Mold and fungus growing on floor boards
When the humidity in the crawlspace gets really high, mold starts to grow like crazy. Mold is a living thing that attacks anything organic (anything that was once alive) like wood. A lot of people don't realize it but the glue holding the fiberglass insulation together has organic material as well. All that stuff has the ability to grow mold and stink.
Hanging and falling insulation
See how the insulation falls down? This is a sign of heavy moisture in the air. When the insulation gets wet, it gets heavy and then it falls down.
Trash and debris in the crawlspace
When there is this much debris and trash in the crawlspace, it is like a mold factory. It is also a haven for things like snakes and mice.