We use a grocery delivery service, and Mollie fell in love with one of their boxes about two years ago. She chewed herself a headrest and sleeps on a bed of tissue paper from various parcels. She will not sleep anywhere else. It is now falling apart.
We cut a hole in a recent box and are hoping she migrates. Of course as soon as we put it down, Catrick went to sleep in it, even though he usually sleeps in a lovely woven dog basket.
Cats love cardboard boxes to play in and sleep in. I think Catrick has found a new bed so maybe the dog bed will be left empty now.