noun
lower animals; lower organisms
Refers to animals considered biologically or evolutionarily less complex, such as invertebrates. Often used in contrast with 高等動物 (higher animals).
下等動物には、昆虫やミミズなどが含まれる。
Lower animals include insects, earthworms, and the like.
Refers to higher animals, typically vertebrates or mammals, in contrast to 下等動物.
Compound of 下等 (lower grade) and 動物 (animal). The exact historical derivation is uncertain; the term is used in biological contexts to refer to less complex organisms.