There are some semantic issues here that should be clarified :-) The term "ground cover" typically refers to a live plant type, one that usually grows close to the ground and/or spreads easily to cover the ground....hence the name.

Pine straw, pine bark and other "soil toppings" are all considered mulches - 'mulching' is really an activity rather than a single product. There is not a single product that is generically considered as 'mulch'. Mulch is any kind of top dressing, both organic or non-organic, applied to the soil surface to reduce soil evaporation, moderate temperatures, reduce erosion, suppress weeds or otherwise cover the soil surface in a protective manner. A non-organic mulch (gravel, lava rocks, recycled rubber products, river rock) will still accomplish a lot of what an organic mulch will do yet not provide habitat for insects like termites or scorpions. But they will need pretty constant attention with regards to weeding and keeping debris out - not as easy to work with as pine straw, bark or woodchip mulch. As organic mulches go, one that is not wood-based should work -- compost or composted manures. A combination of a non-organic mulch (like gravel) immediately adjacent to the structure and then the rest of the bed filled in with an organic type of mulch (bark, pine straw, etc.) will provide for both ease of maintenance and aesthetic considerations. Or you can go the living 'mulch' route and plant ground covers :-)

How do they get in - the door, or somehow through openings in the house? The reason I ask is, would keeping your front door area clear of plantings help? You could make a fairly big flagstone or brick landing that relieves you of needing anything mulch-like close to the door.

KarinL

I've had to do the opposite--I had to cut back all the pachysandra ground cover from around my house, as it was attracting mice and chipmunks toward the house.

Best to keep a foot or two of open space all around the foundation. Use pavers or other material which is easy to keep free of weeds and encroaching plants. That would help deter scorpions, and other bugs as well.