Generally, it is called a "community" (especially when it contains more than one species) but various collective terms are used for animal groups, such as herd, pack, colony, swarm, flock, or gaggle.
school
A society. Society is derived from a word meaning "companion" and companions are the same organisms living together. Definitions of society include, being in the company of others, an organization..., living together in a community.
A colony
A group of Chipmunks is called a "sweet" of Chipmunks! Isn't that cute?!
A commune.
invertibrates
He probably make the assumption that you are his girlfriend BECAUSE you are living together.
Owls group together in a parliament.
A species, only two animals of the same species can mate and have viable offspring (offspring that can also reproduce)
In Afrikaans, a group of fish is called a "visskool." The term is used to describe a school of fish swimming together. This concept is similar to how groups of other animals are referred to in Afrikaans.
A group of herbivorous dinosaurs traveling together is called a herd. A group of carnivorous dinosaurs traveling together is a pack.
A group of organisms of the same species is called a population. A group of different species living together is called a community.