Pigs need mud psychologically and physiologically. My natural pig farming system provides a mud 'bath' in one corner or side of the pen. Kept wet with water this provides a splendid cooling wet water bath. Left dry, the natural coolness of the soil provides the cool that a pig seeks. A pig doesn’t want to lie in wet mud all day and night, so our natural pig farmingpractice is to add water during at certain times of the day when the weather is hottest, and then let it dry naturally. We apply the water with a watering can (we're very low tech) which enables the pigs to get a cool shower as we pour.