Where do you buy the sand path on my free zoo game

If you look at the little icons on the top of the screen, there is one with a shopping cart. (The store) Click to buy products. At the top of that screen, there is another icon with a little house on it. Click on that one. Underneath those icons are sub icons. If you click the sub icon with the little house on it, you can buy paths or buy something to remove them!