Talula is obsessed with fetch. I have to put her balls up at bedtime so that I don't get one in the face in the wee morning hours. She has taken to pulling all the fuzz off of tiny tennis balls, then when they're bald they get all slimy when she retrieves them. It's so gross.
She'll get overheated and her tongue will be hanging out the side of her mouth with a tennis ball firmly between her teeth. Then I have to make her take a break. She now knows where I hide them and will sit and look up at the spots she thinks her balls are at.