The flapping of a tent in the wind can be both an annoyance and a safety issue but there are things you can do to alleviate the problem. The first step is to decide if it's worth keeping your tent in a windy location or not. If possible, it's best to find more sheltered ground for pitching the tent, even if it means moving further away from your intended destination. If you do need to stay, you can make several modifications. The most effective is adding guy lines every few feet along each side of the tent (at least four on each side). And make sure your tent stakes are big enough to hold the tent down!