If he keeps the routine up for a few days, he will find a dead mouse on his doorstep after a week upon getting home.

She won't get near him and she lost interest in observing him, but he is giving her food, so she feels like a token of thankfulness is in order. One meal a day being covered makes everything else easier, and this is good food that nobody else is going to get - the background radiation of his presence keeps all other animals at bay even when he isn't around, it seems.