EDOLT is on the money had the same problem but if I got up in the night I would take the pup out no matter what rain/snow. One thing was my pup was on the roam down stairs with me so I would close the cage dr. I had to learn the hard way when she wanted out she wouldn,t bark or wine so she would leave her mark at the dr and come back to me as nothing had happened. After getting a wet sock Istarted to watch if she went for the stairs to the out dr she would sniff at the dr and look and wait dr no open leave a calling card. So I tied a bootlace from the drknob to about 5"s off the floor with bells on it . She would sniff at the bells moving them around which told me to get my but in gear and let her out. It sounds dumb but it has worked I told afreind who take,s in foster pups or abused dogs works every time.