There are a few terms that could be used to describe a complex organized group of organisms, depending on the level of organization you're looking at:

For the highest level of organization, you could use:

* Biosphere: This encompasses all living organisms and their environments on Earth.

* Ecosystem: This includes all living organisms within a specific area and their interactions with the physical environment.

For a smaller, but still complex group, you could use:

* Community: This refers to all the populations of different species living and interacting in a particular area.

* Biome: This is a large-scale ecosystem characterized by its dominant plant and animal life, often defined by climate.

For even smaller groups, you could use:

* Population: This refers to a group of individuals of the same species living in the same area.

* Species: This refers to a group of organisms that can interbreed and produce fertile offspring.

In addition to these, you could also use:

* Society: This refers to a group of organisms of the same species that live together in a highly organized and cooperative manner, like ants or bees.

* Trophic Level: This refers to the position of an organism in a food web, based on its feeding relationship with other organisms.

The most appropriate term depends on the specific context and the level of organization you are referring to.