I doubt the tarp idea would work, for a couple of reasons.
First, there would be a tendency for moisture to stay inside, even with a hole to "breathe".
And second, you would actually be creating a *more* hospitable place for them to crawl into, since spiders would love the dark, mice would welcome the "safe place", and the snakes would follow.
I would think that it would be best to do the "neat piles", which involves stacking as you cut & split, but it leaves ends exposed and I would think would invite less infestation. There's more light and exposure to the weather, even if covered with a tarp on top.
You hammer stakes into the ground on both ends of your "pile", then stack wood in-between. You have at least one end of the wood exposed to air and light, and take wood from the top, gradually exposing more and more wood, and chasing critters elsewhere as you do.
One pic, stacked between trees: http://www.jaygaulard.com/blog/wp-content/...e-wood-pile.jpg
Illustration: one cord of wood
square pile: http://olsonfirewood.com/images/cord_field.jpg
And I would just always use a good pair of gloves when someone gets the wood. Protects your hands in several ways!