I often take Ferdie into various campus buildings when I have to drop things off or pick up things and each building has commercial carpet squares in the public areas. The carpet pattern is different in each place but basically brown/dark gray in color and Ferdie balks each time we go in. He has to be coaxed to move through the hallways. I finally realized his eyesight sees the carpet differently than we do and it seems like he believes he will fall into a hole when on the carpets. Then i saw this photo last night and I'd be willing to bet this is exactly how our dog sees the carpet squares and I don't blame him for not wanting to move.