My 3 month old sleeps in her potty spot?! Why??

[Michelle_Rolfsen]

I have a nesting box for her that she refuses to sleep in. She slept in her soft pile of blankets until a couple of days ago. Now she's decided to make another nest where she normally goes potty?! She has a 3 tier cage set up and for whatever reason she decided to make the 2nd level her main potty spot. She does very well with her potty training! As this is where she goes potty even when she's out of her cage! She goes back to that place to do her business. I just cleaned her cage out a couple of days ago and she had pottied there a couple of times, but then decided to make another nest there... why would she do this? What can I do?

[KCullen]

I haven't had this with females (assuming she's an Eastern Grey, her estrus will hit around 6-8 months of age), but I have had several males who want to let the ladies know that they have nothing to offer from their prerelease enclosures, so they rub themselves with urine and have a "gross junior high phase." This hits around the 3-4 month mark maybe? I'm not sure if it's personal expression, something they come up with to make more work for me, or just because they're adorable little monsters who are constantly finding new ways to challenge me, but they are sticky, smeary, and no longer kissable. I know that this is how they let me know that they want to start acclimating to an outdoor enclosure. That behavior aside, is her urine or feces different? Urine especially smelly? Does she seem to be straining? Is it darker (brown or reddish) from blood? Sudden changes in potty habits are a sign of illness.