Overview
Animal (動物, dōbutsu) refers to any living creature in the animal kingdom, so it can be applied not only to vertebrates, including the familiar mammals, reptiles, amphibians, birds, and fish, but also to arthropods such as insects, mollusks such as squid, cnidarians such as coral and many other creatures. Of course, humans also fall into this category.
However, it often refers to mammals and birds excluding humans.
The same tendency can be seen in pixiv.