I have a new guinea pig and am creating a cage. Right now, I have a big lower level and a loft. I haven't made the ramp yet, so he's just in the bottom part. The cage is open, which I LOVE. We do not have pets, and it's been wonderful for our kids to be able to interact with him without needing to hold him. However, I am worried once we have a ramp and loft, it won't be safe enough. I'd like to just do coroplast that comes up 6 inches in the loft. Is that okay or could he jump over that? It looks like some people have that. Also, I like the coroplast (is that what it's called???) with ramp directly attached, but I'm worried that won't be enough support. Our pig is VERY big. I see a lot of people talking about bent grids....what are those? Do you actually bend them or do you buy bent grids?