Ants are small, but they achieve great things by working together. A colony can contain from a few dozen to millions of ants, and each ant has a job. Some look for food, some care for the eggs, and others guard the nest. When a worker finds food, she leaves a trail of chemical scent on the ground as she walks back to the nest. Other ants smell the trail and follow it, and as more ants use the path, the scent becomes stronger. In this way, the whole colony finds food without a leader giving orders. Some ants can carry objects many times heavier than their own bodies. Because of their teamwork, ants are often used in stories that teach children the value of cooperation.

Question: What is the main idea of the passage?