Sleeping outside the pouch...

We just have a question about our gliders, who are doing this new thing I'm not sure if we should be concerned about or not. They are twins, girls, and don't have any health issues or otherwise, and have been great pets thus far.

Recently they've been choosing to sleep outside of their pouch (anywhere else in the cage). We have two pouches for them (one is used while the other is laundered from time to time). They have always slept in either pouch without hesitation. Until recently. To note though, if I go in and put them in the pouch they go right in and sleep, no problem. It doesn't make sense to me. Do you think its just random/harmless, or is this a sign of something I should look out for?

Any advice is great.