My Kronks inside home- for over night and during bad weather- is a 3x5 dog crate. It holds my 2 full grown Great Danes, so it has plenty of room. I need ideas for substrate. I cannot fill it with soil or bark. It does have a solid boundary 8 inches high all the way around it, but because of the slide plate style bottom and the door, it will not hold anything like that. My husband insists on newspaper, but I'm afraid he eats it, or will, and while it is vegetable based ink- it is staining his belly when it gets wet. I also try to keep hay inside it, but he eats through it rather quickly. I am thinking of those little plastic greenhouses to hold soil and plant in. Does that seem doable? He isn't restricted to the enclosure... he is often being followed by one of my many children or bonus babies walking about, being bathed, handfed, held, or put outside (with supervision) in his 18x25 foot grassed enclosure...