I have two feral cats that I feed twice a day.  I wanted a place for them to hang out.  Sure enough, the male cat was the most curious and crawled up to the third level on the second day that I put up the cat house.  He has slept in this house twice now.  I am thinking about removing the step on the second level because it gets in the way.  Cats are so athletic that the step is not needed.  I wrapped the house in a tarp to keep the insides dry.  Now my cat is not so sure of staying in it but we'll see.