Such pens--necessary in a variety of cases other than those mentioned--need not exceed eight or ten feet square, and should be built of light materials, and fastened together at the corners, so that they can be readily moved by one man, or, at the most, two, from place to place, where they are wanted. Their position should be daily shifted, when sheep are in them, for cleanliness and fresh feed. Light pine poles laid up like a fence, and each nailed and pegged to the lower ones at the corners, or laid on, are quite serviceable. Two or three sides of a few of them should be wattled with twigs, and the tops partly covered, in order to shield feeble lambs from cold rains, piercing winds, and the like. Young lambs are subject to what is commonly known as "pinning"--that is, their first excrements are so adhesive and tenacious that the orifice of the anus is closed, and subsequent evacuations prevented. The adhering matter, in such cases, should be entirely removed, and the part rubbed with a little dry clay, to prevent subsequent adhesion. Lambs will frequently perish from this cause, if not looked to for the first few days. The ewes and their young ought to be divided into small flocks, and have a frequent change of pasture. Some careful shepherds adopt the plan of confining their lambs, allowing them to suck two or three times a day. By this method they suffer no fatigue, and thrive much faster. It is, however, troublesome as well as injurious, since the exercise is essential to the health and constitution of the lamb intended for rearing. It is admissible only when they are wanted for an early market; and with those who rear them for this purpose it is a common practice.