Considering the way that Ziva can gnaw a very large bone into shreds (and eat them), and that she has been known to chew various objects not intended for her consumption (e.g., she removed an elastic strap from one of my concert shoes), you might think that I would be concerned about the fact that shoes are regularly found on any of four of her "parking rugs". These shoes are normally kept in a large bucket by the front door.
However, after two such chewing incidents, things have settled into a groove where it is apparent that our cunning quadruped simply likes to have footwear near her as a comfort, particularly when she is alone for awhile. We have already heard some of your comments to the effect that dogs like strong smells... Be that as it may, Ziva is a comely foot-fetishista. Although I love Greek cheese, please, let's not have any puns involving feta, okay? But then, this blog post is enough off-the-wall that I really should allow open season in the comments section, as usual.
By the way, the shoe is completely intact, no missing sole, it just happens to have an insole that is a pretty good color match for the rug. Maybe Ziva has a genetic mutation that gives her trichromatic vision (like humans) unlike other canines and most mammals (which have only two types of color receptors, somewhat like humans with red-green color blindness). Of course I'm engaging in fantasy; I think Ziva was just lucky about the color. On the other hand, I could not identify hundreds of people by traces of their odor, hours after they passed through an area.