After studying Foster Kitten's latest progress for a few days, it's official: She now opens the heavy external door to the back porch at will to let herself in.
And ignores any request to shut the door behind her.
Are we seeing accelerated evolution?
Did we indeed have radioactive spiders in the house as I might have suggested?
Will we come home from work one night to find a suitcase with our clothes on the porch and the door locked from the inside?