You don't say if the insulation is fibreglass, but we'll assume it is. If the insulation in your crawl space has been installed with the craft paper side toward the dirt, then you will have a problem (a lot of homeowners make this mistake because they are used to insulating walls and having the paper side toward them). The craft paper will hold in moist air that comes from the humidity inside your home and seeps through the floor. Because this moist air is unable to escape through the paper, it can make the insulation soggy, and therefore a haven for all things that crawl (not to mention molds, mildews, etc.) You should replace the insulation with either non-faced insulation, or turn the insulation around so the paper side is immediately below the subfloor. Have fun.