I always think they leave a little bit so that if they get really hungry and want to come back they know there will be something there. I think it stems from their days when they had to fend for them selves. They never knew when they would eat again so sometimes they left a bit so they had something to come back to later.
Good suggestion with the snow. I'll do that tomorrow morning. It is funny how she is not eating all the food in the bowl. She leaves a little and it is still there in the morning. Even when she was coming two times a day to eat, her normal portion I gave her was a 1/3 of a can of high quality wet food and 1/8 cup dry and she ate most of it. I don't think she is a big eater. Even when she was missing for a week and showed up she ate a little more than 1/2 can wet and went back in her house. I hope I see her in the AM. Will keep you posted. Good luck with yours too.
My Shadow never ever finishes all of his food. He always leaves a little bit in his bowl. I always say he is not a member of the clean plate club. I think he wants to know that there will always be something left in the bowl for him to eat late.r
Keep leaving her food. It is just too cold to withhold. She may be coming back over night and then just leaving again.
It is way too cold for any other creatures to be out. I have the cameras on my deck and haven't seen anything at all in days. I usually see the opossum, but it has been MIA too. I still get some deer, but they don't come near the deck.