Boarding up the deck

Scott and I were in a Home Depot last night...looking to buy some board for our deck. I think that there are bunnies and kitties that get under there, and when my parents bring there dog over she insists on trying to get under the deck. We wanted to put something up along the sides so that she wasn't able to get under there any more. It just causes her to get very dirty and sometimes even stuck. She's too big to be getting under there. We did find some board that we want to buy, but have to wait until tonight when Scott can bring home a truck....that's the only way we'll be able to bring it home.