We've been using C&C bunk beds in the pigs cage for the past few months (DIY instructions on how to build your own). As expected, some cavies use the upper loft more often than others.
Revy and Abby-Roo take turns using the bunk bed. Every so often Abby-Roo can be spotted nestled in the corner. At other times Revy can be seen sprawled across something fuzzy. The more cage accessories, the better!
In the cage next door, Truffle and Peaches can frequently be seen napping upstairs. Surprisingly, athletic Belka rarely decides to hop up for a snooze - the only time she bothers to is when the pellet bowl is placed there.
Poof is perfectly willing to sleep in the top bunk, often curling around the bowl in order to keep an eye on her precious pellets. And of course, the lower bunk is popular with all the pigs. Who can resist a good hiding spot?