Turkey calls are the musical instruments of turkey hunting, and like learning to play a piano, guitar or fiddle, practice makes perfect. Of all turkey calls, friction calls are the easiest to use. Box calls, slate calls and push-button calls are types of friction calls and all work using the same principle--one piece is rubbed across the other to make sounds like a turkey. The most popular friction call is the box call. To use a box call, slide the lid (called the paddle) across the side of the box to make a yelp. A yelp is one call a turkey uses to answer another turkey's calls. It is also a way to bring flocks together after they have split up. On most box calls, one side of the box makes a higher-pitched sound than the other. This lets you imitate more than one bird, so you can make it seem like one bird is yelping and the other is answering. As you perfect the yelp, you can move on to harder calls such as the cluck, fly-down cackle and gobble. With a little practice, you'll be calling in gobblers in no time.