What is a word for large colonies of animals?

There isn't one single word that perfectly captures "large colonies of animals" as the most appropriate term depends on the specific type of animal and the nature of their colony.

Here are some options, depending on the context:

General terms:

* Colony: This is the most basic and common term, applicable to many types of animals.

* Aggregation: This refers to a large gathering of animals, often temporary.

* Swarm: This term is often used for insects, like bees or locusts.

* Flock: Used for birds.

* Herd: Used for mammals like cattle, deer, or elephants.

* School: Used for fish.

More specific terms:

* Hive: For honeybees.

* Anthill: For ants.

* Termite mound: For termites.

* Rookery: For birds like seals or penguins that nest together.

Descriptive terms:

* Massive colony: Emphasizes the size.

* Dense colony: Highlights the concentration of individuals.

* Thriving colony: Implies success and growth.

The best word to use will depend on the specific animals and the context in which you are using it.