A predatory ciliate protozoan moves through pond water. This unicellular organism's locomotion is effected by the rhythmic beating of many hair-like cilia, as well as by flexing movements and extrusions of contractile parts of the cell. Ciliate protozoa are tiny single-celled organisms found in water. They feed on bacteria and decaying organic matter, which they filter in their primitive mouth, known as a buccal cavity.