Locomotive organs in small organisms are usually flagella and cilia. Those organisms which possess flagella have only one or two flagella, however, those organisms who have cilia can have thousands of small cilia surrounded their body. These organisms usually fall in the phylum Protozoa. For example, paramecium who have a few thousand cilia on its body which help the organism in locomotion is a protozoan. Cilia are also present in the mammals like there are more than 107/mm2 cilia in the respiratory track but they do not have any concern with locomotion. Another important point is that although a number of organisms in phylum protozoa have cilia but still there are many organisms which do not have like Chlamydomonas(only have flagella).
