Along the way, she releases a complex cocktail of chemicals to assure that, if her hunt is successful, other ants can locate her trail and lend a leg (or jaw).
Finding no sustenance, she hightails back to the trail junction and leaves another sign for her nest mates: “dead end.”
She tries another route, and this time she stumbles onto a live giant caterpillar that would feed many in her family. But it is too big to handle alone. Firing a dazzling array of chemicals into the air, like sounding a trumpet in the heat of battle, she summons reinforcements who soon arrive. Not only do they know how to find her but they also bring the necessary tools and personnel to kill the caterpillar and bring the body back to their nest.
Ant Sting with Venom
Here a worker fire ant (Solenopsis invicta) is shown in stereotypical defensive posture, her sting extruded, waving a droplet of venom in the air. Photo © Alex Wild
Ant communication is one of the great wonders of our Father’s world. The ants’ efficiency at foraging has even inspired business and computer problem–solvers who are looking for new techniques to come up with quality answers in the quickest time.1
To communicate is to impart information, via a “package,” from sender to receiver. The receivers must be able to decode the message and inform the sender whether they understand. In the example above the lone ant communicated her messages by way of chemical “packages.” The precise mixture of chemicals conveyed where she went, what she did, whether to follow, and how to help. Her colony mates had to decode her messages and act upon the information they received.
These advanced communication abilities enable several species of ants to maintain complex social organizations. Only a sampling will be mentioned below. So complex are some of these societies that they have been dubbed superorganisms. Their sophisticated networking abilities point to the Great Communicator, Jesus Christ, who designed creation to reflect His attributes (Romans 1:20).
Communication by Chemicals
Ant Alarm Posture with Eggs
Alarm posture in an acrobat ant (Crematogaster emeryana), gaster held high and sting extruded. These ants don’t use their stingers to sting; rather, the organ is used as a brush to broadcast chemical signals to nestmates and to smear chemicals on attackers Photo © Alex Wild
Ants communicate with each other in a dizzying range of ways, but chemical signals (pheromones) appear to be the most important method.
The ant’s outer layer produces a suite of chemicals that perform many different but vital functions. These unique chemical combinations give each ant its own individual profile. Other ants can use their antennae to “profile” each individual, identifying its group membership, reproductive status, and job skills. The antennae are the ant’s primary decoding structures, used for profiling other ants, receiving warnings, and detecting both the direction and intensity of airborne scents.
Ants have many different glands to produce message-bearing pheromones. Nearly forty such glands have been discovered so far among various species. The ants employ these chemicals to produce messages for a variety of tasks, especially foraging.2
Among the various ant species, biologists have discovered forty different glands that produce message-bearing chemicals, called pheromones.
For example, ants will lay down either short-term or long-term memory trails, depending on the importance of the trail. The longevity of the trail is determined by the chemical left behind. For instance, Malaysian ponerine army ants have poison glands containing a pheromone that dissipates quickly. They use it to make short-term memory trails to call in reinforcements for a temporary job, such as recruiting nestmates to capture prey.
Other pheromones last longer. This allows ants to establish extensive networks of trails, find their way back, and search for food systematically. Long-term memory trails can last from twenty minutes (Malaysian ponerine army ant) to several days (pharaoh’s ant).
Some species divide the labor of laying down trails and foraging. Consider pharaoh’s ant workers. Some keep their antennae in continuous contact with the ground to detect long-term memory pheromones, while others follow behind them and maintain the trail by adding more chemical as needed. Still others are not responsible for trail marking but use the trails to forage for food.