Our first pair of piggies currently has a cage created from their old cage being dismantled. Our newer pair came with a cage that doesnt come apart easily. However they came with a dog pen that the old owner initially said was for letting them graze outside but we've already got a pen outside and haven't used the dog pen once. Has anyone made a cage out of dog pen? I measured it out and it would be around 18ft². And what would I use for the base? Our other piggies have a clear plastic tarp attached to a giant piece of cardboard (couldnt find coroplast anywhere) but we dont have any cardboard near that size left.