Nematodes are a highly assorted group of invertebrates occupying many terrestrial and aquatic habitats. Recent research has focused on the examination of nematode life history and biological traits to reflect the key functional attributes and infer the effects of environmental variables and human activities. In this book, the authors discuss the interaction between lectins and nematodes, biodiversity and distribution of nematodes belonging to the families Longidoridae and Trichodoridae in different habitats, analytical method for chemical characterisation of nematodes, and the use of plants as natural sources of nematicides.