Gracie is very interested in the pile of dirt that develops when I sweep. She'll follow me around the room, watching the broom closely, even moving her head back in forth as the broom moves back in forth. Then when I get to the pile I always tap the broom on the floor a couple of times to dislodge anything that might be clinging to the bristles. She'll get all stiff and at attention and seriously stare at the broom. As soon as I move off to start sweeping in another area, she'll study the pile very closely and even paw at it to see things better.
I'm not sure if she is upset that all the wonderful dirt, twigs, grass and dustbunnies that she has been collecting are being rounded up from the 'proper places'. Or if she maybe doesn't see the dirt too clearly until I tap the broom and it magically apprears. Either way, I usually have to lock her out of the room I'm sweeping because she scatters the pile faster then I can sweep it up.