I've also had some pretty destructive rats in the past so I don't allow my rats to free roam at all. I keep a rat safe walled-off play area for my boys.
Some people cover their bed with an old blanket or sheet and use that for playtime. You can set up all kinds of boxes and stuff for them to climb on your bed. Another option would be some sort of playpen. You can make playpen walls out of stuff like cardboard or coroplast or you can purchase a [manufactured playpen]. For playpen walls, I recommend at least 28" tall.
Some people cover their bed with an old blanket or sheet and use that for playtime. You can set up all kinds of boxes and stuff for them to climb on your bed. Another option would be some sort of playpen. You can make playpen walls out of stuff like cardboard or coroplast or you can purchase a [manufactured playpen]. For playpen walls, I recommend at least 28" tall.