Total newbie here, starting to build the digs for our ladies. Purchased the plans for "The Garden Coop" and so far so good. We are almost ready to dig our trench, bury the hardware cloth and set up the walls. The coop is going to be set where grass is already existing. The question is, do I need to remove the existing grass or just let the ladies do it for me when they move in? I plan on using pine shavings for the litter. Thanks in advance for the feedback!