The article presents an analysis of Lithuanian folk entomonyms (insect names). The methodological approach is based on complex linguistic research, where semasiological and onomasiological aspects are combined. The main sources of empirical material are the LKŽe and 13 dialect dictionaries. Detailed analysis of lexicographical sources helped to establish the boundaries of the thematic group of entomonyms. Entomonyms are studied as the result of a nomination and motivation process. The analysis helped to determine the relationship between motivated and unmotivated members of the thematic group, the dominant nomination types, ways, instruments, the most important features of motivation, and the variety of models of motivation.