Thanks for the compliment on my cage!
To answer your questions:
They have never fell off the ramp, I used old carpet over the wood and they do just fine on it. Using the carpet you will make sure they don't slip on the wood. Just keep in mind if the incline is to steep they won't use it so make it so they
don't feel like they are going to fall off.
As far as sleeping together they almost always sleep on the same level but in their own house. Every now and then mostly during the day you will see one on the bottom level and one on the third but they always sleep on the same level during the night hours.
I would add on to mine but I wouldn't be able to reach it to clean it out (
).
Again, if you need any help feel free to email me at
yataebo@cinci.rr.com
Good Luck with your cage, make sure you post a picture when you are finished!