Even though the ants use avoidance most of the time this is viewed as a type of defense so that in the case of a large confrontation, many ants can be present on a marked territory (Whitehouse & Jaffe 1996).

Roces, Holldobler, Tautz, Kleineidam, and Krumme found an interesting defense mechanism in the foraging column of the leaf-cutting ants. In the foraging column the minima workers “hitchhike” on leaf fragments carried by the workers. The purpose of this is that the large workers will defend the small workers from parasitic phorid flies.



Ant on its Environment

The leaf-cutting ant has a profound effect on its environment. In some areas the leaf-cutting ant is a determining factor of forest dynamics and composition (Heraldo and Cherrett 1997). When a leaf-cutting ant nest moves into a new environment they immediately start to chew up and move leaves and seeds. Vasconcelos and Cherrett (1997) found that the damage done by leaf-cutting ants negatively affected seedling survival and growth. They also noted that time most dangerous to a seedling was between 3-9 months. Thus the older the seedling becomes, the less chance it will die from being chewed on by the leaf-cutter ants. The ants have a preferential taste for certain types of plants. This leads to selectivity and thus the ants can change forest composition. Since the ants mainly go after leaves of seedlings, populations tend to increase after clearing of mature forest (Heraldo and Cherrett 1997). Thus the ants can reduce tree establishment by two ways. They can act as seed predators and seedling predators. Another way that the ants effect the environment (this one can be positive) is through facilitated succession. This research was done by Brener and Silva (1995). It was found that some trees grow preferentially on abandoned leaf-cutter ant nests (Bucher 1982). It was found that between the open grass lands and forest there was numerous ant nests. Here there are many seedlings and smaller trees as the forest starts to colonize the savanna. This is where many leaf-cutting ants are (for reasons already described). The woodland trees changes the soil which the facilitates the establishment of shrubs which allows the further survivorship of near by ant nest between the forest and grass land. As show by Brener and Silva’s (1995) results the ants benefit from direct food availability and better habitat conditions and as the nest grows, it promotes changes in soil and nutrient status improving conditions for the survival and growth of trees. Nitrogen, phosphorus, potassium, magnesium, calcium, sodium, moister, organic carbon, all increased due to ant nests. The scientists found that groves would grow larger and more quickly than those who had no ant nests.