When it first arrived, both my adult cats slept on it - I kept the box around for a whil because KC had a good time climbing in and out of it with his toys... I have not seen them on it for a week or so - must be a little uncomfortable for them; neither has entered the cave - not sure why as one loves to get in boxes, etc... they both use it as a scratching post... overall I think it is great, my kitty language is a bit blurred though; I am going to put a little larger pillow in the top... perhaps that will be more comfortable for them - It arrived on the exact day as advised; it was easy to put together; and all pieces were there - nothing ripped, torn or broken! Thank you Wayfair!