I am in the process of converting my 24 x 24 fenced garden into a new chicken/duck pen. We will be replacing the fencing as it is currently fenced with field fencing (keep our dogs out so they don't destroy or eat the garden). Can I reuse the fence we take down from the garden on the top to enclose the pen? Field fencing has the 6" rectangles that start small and get larger as they go up. Our concerns are foxes and we also have hawks that fly around as well. Are these holes small enough to keep foxes/hawks out if they are on top?