Does you dog randomly run around the yard looking for sticks and dropping them at your feet? Then your dog has Stick Gathering Syndrome(SGS). It seems to be popular among herding dogs such as Border Collies. They will find any stick, any size and drop it at your feet, waiting for you to 'pick it up' and throw it away.
There isn't much you can do about it except for cutting down all of your trees or keeping your dog indoors while you sweep the yard of sticks every day. SGS stays with your dog for life and you just have to learn to live with it. Try a ball or a Frisbee, but if you own a border collie, you know there is also OWF(obsessed with the Frisbee) to worry about and that can be much worse!