Female rats often start 'nesting' after they've become pregnant, bunching the shavings together.  In the three months I've had Andoria, she's never shown the slightest interest in it.

Then she spent a week with Brutus.

Things seem to have changed around the ol' ranch.  Here's one corner of Ratville:
 

 
And here's the other corner, with the aforementioned Andoria:
 

  
Do you think Andoria is trying to tell us something?