If you've ever spilled a glass of water on a roll of Scotch tape, you know that many tapes lose their stickiness when they get wet. Water-activated tape, however, is unique because its adhesive is only activated by water. When the adhesive on water-activated tape is moistened, it bonds to whatever surface it is applied to. If you apply water-activated tape to a box and the box later winds up stuck in the rain, you can rest assured that the adhesive will remain intact.