take a tissue box and attach to the top of your cage using pipe cleaners and you rats will get creative trying to get up there and when they do they will sleep in there
when i first put it in there my one rat went in there then the next and now today all 3 of my rats are happily packed in there like sardines
when i first put it in there my one rat went in there then the next and now today all 3 of my rats are happily packed in there like sardines