I know pei are a very clean breed and wondering wether this is part of it?
Pearl and Jezebel were clean and dry at 8 and 9 weeks respectively, Storm however.............well

He is now 4 and a half months and has been clean and dry for a couple of weeks but before that if he had a bowel accident, he would try and cover it with whatever he could find.............blanket, cushion etc. I have never seen this before. He only did this for house accidents and doesn't attempt to cover when in the garden, so I have to assume it was some form of 'guilt' although all books tell you dogs don't feel guilt/remorse etc