Hello, I have five hens (hatched last spring) that free range throughout my yard. Because they are out most of the day, their run is relatively small, and is difficult to clean. It's just dirt at the moment, but we are expanding it this weekend. I was wondering if it's advisable to use pea gravel? I know that people with ducks often do it (I have two ducklings in the brooder right now...so cute!) and swear by the ease of cleaning it. Any suggestions?