Water pearls, also known as water beads or hydrogel beads, are small beads made of a polymer that can absorb and hold large amounts of water. They are commonly used in floral arrangements and centerpieces as a decorative filler and to keep plants hydrated. They are also used in various crafts, sensory play, and in gardening. They are usually made from a non-toxic, biodegradable polymer and come in a variety of colors. They start off small and hard, but when soaked in water for several hours, they expand and become soft, jelly-like beads. They can be reused multiple times by simply re-soaking them in water.