Elementary Deduction, Watson

I returned from shopping this morning to find a small Christmas cookie (previously on a plate on the counter) with one small bite out of it in the middle of my kitchen floor. Proceeding into my bedroom, I found Mittens curled up sleeping inside the suitcase lying empty on my bed.

From this I can only deduce that she is already suffering pre-trip separation anxiety and has been indulging in some emotional eating.