Morphological, physiological, and ecological adaptations of bdelloid rotifers (phylum Rotifera, class Bdelloidea) to the conditions of soil and land biocenoses are presented. The morphological structures, obligate parthenogenesis, and anhydrobiosis allowed these rotifers to colonize various semiaquatic areas with sharp fluctuations of environmental conditions: edaphon, coniferous and deciduous litters, mosses, and lichens. The role of bdelloid rotifers in the food web and environmental indication was mentioned. The controversial problems of the origin of this group of worms were broached.