We crate or pen when we are not able to watch Coby. (Reggie has the run of the house but he's 11 and doesn't get off the couch if no one is here to coax him
) Coby loves his crate (and it's one of the tiny ones - just room to turn around) and goes in without being asked whenever we put our coats on. If we're going to be gone for a long period of time, we set up the x-pen (we put a thick plastic sheet over the top secured with binder clips in case he'd try climbing out the top).
My suggestion woudl that for Carlos' safety, in addition to your sanity, he shouldn't have a way to get into things when unsupervised.
Good luck with this "stage".
