Hi. Our 9 week Plummer terrier is pretty good at using the puppy pads to wee/poo on but at night when we put him in his crate he soils his bed. He is quiet all night until about 4.30/5am but I'm lost as to how to stop him using his bed as a toilet! Should I keep the crate door open so he can go and use the pad in the night? Many thanks