I just don't get it...

I send the kids outside to play everyday. And most of the time they go adventuring, but the past several days they've been camping out on the front porch. We have 4 acres of land, some densely wooded, a great swing set, a paved driveway and basektball hoop, a gravel part of our driveway for digging in and spinning out on their big wheels, but no...they camp out on the porch! I even tried to get them to camp out under the shade of one our many trees, but they would not be persuaded. I think it must be the electrical outlet that they have the cd player plugged into so they can listen to their book on cd...go figure!