sponging

Sponging is the act of using a sponge to apply, wipe, or absorb liquids. Sponges may be natural, derived from marine organisms, or synthetic, manufactured from polymers. In everyday language, sponging is commonly used for cleaning dishes, surfaces, or applying cleaning solutions, and also for bath or cosmetic uses.

Natural sponges belong to the phylum Porifera. They are simple aquatic animals with a porous body plan and no true tissues or organs. Water flows through pores into a canal system, and food particles are filtered by specialized choanocyte cells. Sponges can reproduce sexually, releasing sperm into the water and producing eggs in other individuals, or asexually by budding or fragmentation. Their skeletons may consist of silica-based spicules, fibrous spongin, or a combination, providing varied hardness and texture. They inhabit a range of aquatic environments, from shallow coastal waters to deep seas, often attaching to substrates like rocks or reefs.

Synthetic sponges are made from cellulose, polyurethane foams, or blends and are designed for absorbency, softness, or durability. They are widely used in households, laboratories, and beauty applications. Because natural sponges are harvested from wild populations, there are conservation and sustainability considerations; some species are cultivated or farmed to reduce demand on wild stocks.

In broader usage, the term "sponging" can also refer to the act of living off the generosity of others, i.e., a person who sponges. The word appears in various contexts and carries negative connotations when describing dependence.