Lilly the Mimic

For a few weeks now, when you growl at Lilly she will growl back at you.  She and I have done that so much that now she will often greet me with a growl when she first sees me.  This weekend I discovered that she's learned a new trick: if she hears you whistle, she'll try to whistle back.  She has no idea how to actually whistle though, so she just makes a high pitched noise to try and imitate the sound you made.