The household item sometimes thrown over trees by Halloween pranksters is toilet paper. The prank is commonly called toilet papering, TP-ing, yard rolling, or house wrapping, depending on the region.
Participants usually throw rolls so that the paper unrolls in midair and drapes over tree branches, houses, fences, and other outdoor structures. The result can cover a yard in long white strands, making cleanup difficult even though the paper itself is lightweight. In the United States, toilet papering is especially associated with Halloween, but it can also occur after school events, homecoming games, graduations, or on April Fools' Day.
The prank is often treated as harmless mischief, but it can become trespassing, property damage, or littering if it targets private property or leaves paper in trees and storm drains. A related mistake is confusing toilet papering with “rolling a house,” which may describe a broader prank that also includes decorations or other messes. The paper thrown in this Halloween tradition is ordinary toilet tissue, not paper towels or streamers.