The use of objects in the pen to reduce tailbiting is not new. Toys' which are on the floor lose their enrichment value to the pigs once they become soiled with manure. Bowling balls, pipes, and other such objects attract a great deal of attention for a few hours or days, but then are abandoned. Hanging objects, such as chains or rubber tubing, maintain the attention of the animal for a longer period, but they too are not heavily used. Chains also contribute to the noise level of the room.
Pigs appear to enjoy manipulating objects which change with chewing.
A rubber hose is more interesting if it has started to unravel. Cloth strips provide something a pig can destroy. Addition of a small amount of straw to a pen will maintain pigs' attention as they manipulate, chew, and eventually swallow it. Straw based systems, or those which add small amounts of straw daily, have dramatically lower levels of tail-biting. This behaviour is most commonly seen in nursery pigs and consists of a pig rooting the belly of another pig, in a manner similar to the way piglets nose the udder of the sow.