he laborers and defenders of the colony. In most ant species there can be sub-castes of the workers, namely majors, media and minors. Relative head and overall body size distinguish subcastes. The majors are the largest of the three and possess a disproportionately large head and mandibles. The function of the soldiers is to protect the ant colonies. The media and minor workers are the most common individuals in an ant colony and perform the majority of the work duties. Minor worker ants also perform a variety of functions depending on the species of ant.
Ant Wars, Competition and Survival. Ants are amongst the most aggressive and war-like of all animals. If ants had a policy of life it could be summarized as restless aggression, territorial conquest, and total annihilation of neighboring colonies. These insects use any of a number of strategies and weapons to reach these ultimate goals. Chemical warfare is prevalent amongst many species including spraying a variety of toxic chemicals in order to repel, confuse, immobilize or even kill their rivals. The soldiers of many species readily assume a kamikaze role in order to “win skirmishes” between rival colonies. One of the most dramatic of these sacrifices is exhibited by a carpenter ant from SE Asia. These ants act as walking bombs. There is a huge internal gland that occupies much of their body that is filled with toxic chemicals. If one of these ants is hard pressed by a rival ant or predator it contract some large abdominal muscles that bursts open the abdomen violently (like a bomb) releasing the chemicals.
The availability or more significantly the limited availability of food frequently is important in colony survival. As a consequence rival colonies frequently develop strategies to maximize their collection of available food. There is a tiny fast moving ant in the deserts of Arizona that utilizes toxic secretions to intimidate and confuse much large honey ants (10 time their size) as they steal food from the larger ant colonies. In addition these tiny ants will frequently prevent honey ants from leaving their nests by releasing toxic chemical down the hole or nest entrance thus driving the former below ground. This of course allows the smaller species to forage without competition from the honey ants. Another form of nest entrance blocking is exhibited by a small ant species in the southwestern deserts. In this case they gather in mass around the nest entrance of their rivals and similarly release toxic chemicals down the entrance. However in addition they pick up pebbles, twigs and other small objects and drop them down the vertical shaft entrance.
Possibly the most elaborate of all documented aggressive strategies in social insects occurs in battles between the tiny woodland ant and the imported fire ant. The fire ants are deadly enemies of the woodland ants with colonies 100 times larger than their tiny rivals. Even though fire ants are much more powerful than the woodland ants both successfully survive in the same area. The secret of woodland ant survival evolves around a specialized soldier (major) and a three-stage strategy to defend against fire ant attack. These soldiers are equipped with huge heads that are equipped with large sharp jaws provided with massive muscles. These do not attempt to sting or spray their enemy with poisons (common in many ants) but quite precisely use their mandible to snip off legs, heads and other body parts. Unless attacked the majors remain in the colony. However, the minors regularly forage for food but are always on the alert for scout fire ants that are looking for colonies to raid. If a woodland ant minor encounters a fire ant soldier close to its colony a violent response is triggered. Once detected the minor rushes to the fire ant in a mock attack but merely touches the potential invader in order to acquire some of its odor. She then quickly retreats toward her nest. As she retreats she lays a pheromone trail by periodically touching her abdomen to the ground. On her way back she briefly rushes up to any other minor alert