Paramecium use two types of locomotion - ciliary movement and metabolic locomotion. Ciliary movement involves the synchronized and metachronous beating of cilia to propel the organism in a spiral path. Metabolic locomotion involves changes in body shape through protoplasmic movement. Paramecium feed by sweeping bacteria and algae into the oral groove using cilia, which then pass through the cytostome and into food vacuoles for digestion. Undigested particles are egested through the cytopyge. Paramecium regulate water content through two contractile vacuoles that collect and expel excess water taken in by osmosis.