Why does Teddy like my shoes?

Nothing makes Teddy happier when I come home than to grab a toy or a rawhide and run around the sofa with it. He runs to me and then runs away, with whatever is in his mouth. But the thing he loves most to run around with is one of my gym shoes. He's not a chewer of shoes, but he loves to just hold the shoe in his mouth and run around with it. He especially seems to love holding the shoe by the laces. He knows he's not supposed to do it, because as soon as I tell him to leave it, he drops the shoe, but it's an addiction he just can't seem to control. Whatever floats your boat!