Nematodes have adapted to diverse ecosystems, including land, inland waters, the seabed, and even within the body of other organisms. However, as nematodes are very small (most species are less than several mm), and have limited mobility, they may be unable to escape threats to their survival, including low temperatures and desiccation. For example, the Antarctic terrestrial species of the free-living nematode Panagrolaimus davidi has developed cold tolerance strategies that enable it to withstand intracellular freezing. In the plant-parasitic potato cyst nematode Grobodera rostochiensis, the eggshell and cyst wall act as barriers to ice-nucleation so that it can withstand temperatures as low as -38℃ and survive the winter. Stem nematodes, foliar nematodes, and entomopathogenic nematodes tolerate desiccation by transitioning into a state of anhydrobiosis by producing substances such as trehalose, glycerol, and myo-inositol. Some individuals have even survived several years in a relative humidity of 0%. Studying such tolerance strategies will facilitate better understanding of the applicability of nematodes in agriculture, forestry, and fisheries.