How should I go about naming groups of animals in Latin? Should I use a single word like grex in all situations, or should I use varying words depending on something?
In English — and I simplify for the purpose illustration — a group of mammals is a herd, a group of birds is a flock, and a group of fish is a school. I can imagine that in different languages the choice of words is based on something else, like the size of the group or whether they are domestic or wild. Therefore I am reluctant to ask for just translations of "herd", "flock", and "school", not knowing whether the Latin system aligns with the English one well enough.
How does this system work in Latin? I am looking for an overall approach or a rule of thumb to this naming issue; any peculiarities can be explored in separate questions. Feel free to paint with broad strokes. My main interest is classical Latin, but other eras are welcome if they come with a nice answer.