latter not needed for an adult cat. i made some edits to it. took an old house from out from an old one and put it on very top flat post, so one cat sleeps up there. I took off the flat piece with the holes, my cats didnt play with that, and i put the other flat peice on that. They dont go in the big house at the bottom because the dog can reach them. I have a long legged boxer. There is a mouse hanging in that house but cats dont even bother with it. the house in the middle is too small for my adult cats and they still use it, but fold up into a ball and legs and arms will stick out when theyre sleep. The house in the middle is not big enough so im wanting to swap that out too but i dont have a replacement just yet. i wish the big house on the bottom was in the middle, that would have made it 5 stars. It is pretty tall too.