The tree in your backyard is home to two cardinals, a colony of ants, a wasp's nest, two squirrels, and millions of bacteria. Together, what do all of these organisms represent?

A community

Explanation:

In ecology, a community is used to describe a group of organisms of different species populations that live and interact together at a particular time in a common habitat or ecosystem.

The two cardinals, colony of ants, a wasp's nest, two squirrels, and the millions of bacteria represent a community of different organisms dwelling at the backyard tree.