I just bought a multi level cage as I adopted another piggy last week and they needed more room, they are still getting used to it themselves but to encourage them to go on the different levels I've put their beds up top and food down bottom so they have to go to both levels to get to what they want, they aren't keen on the ramp yet and squeak the whole way down it, but they will eventually realise they have to use the levels, when you take them out put them back at the different levels so they get used to each one and hopefully in time our piggys will love our new cages for them.