Form and Function

      Atta cephalotes have many ways that their form and function depends on what job they do. The two main points that will be made on this page are head size and their ability to detect moisture.

    The role of head size has everything to do within the colony. The more developed colonies will have a larger array of sized workers than a new colony. When the colony starts out, most head widths are generally smaller, but still medium size (Hölldobler & Wilson, 2011). These medium head workers will be in charge of doing an array of tasks (Hölldobler & Wilson, 2011). But as the colony grows to be bigger, which takes a few years, the specialization of head width becomes more important (Hölldobler & Wilson, 2011). Age does play a factor into this, but for the most part, overall head size plays a bigger point. The head size will grow over time and the worker might be assigned to a different task (Hölldobler & Wilson, 2011).

    There is no exact measurement of head size to role. It is more dependent on the individual colony.  This is due a number of things: colony size, overall width of each individual’s head compared to the others in the colony, and what is needed most within the colony (Hölldobler & Wilson, 2011). A. Cephalotes have a spectrum of head widths, but are categorized into four main groups; smallest, second smallest, second largest, and largest (Hölldobler & Wilson, 2011). There is a sort of assembly line that takes place from the largest to the smallest (Hölldobler & Wilson, 2011). The smallest tend to the fungi. This is important because this fungi is the food source for the colony. The second smallest transport leaves from the outside of the nest to the gardeners (smallest heads). The second largest forages and cuts the leaves, then brings them back to the nest. The largest also help the second largest, but they have another function (Hölldobler & Wilson, 2011). They are the biggest; therefore they protect the colony from invaders such as the Army Ants. They defend the colony by using leaves as barricades (Swartz, 1998).

    There are other ways these ant’s form and function react to their environment. A. cephalotes, along with other Atta species, grow their fungi in most moist chambers within the nest. A. cephalotes have adpated the ability to sense the humidity change within their nest (Hölldobler & Wilson, 2011). When the growers sense that the chamber that they are currently tending to their fungi in is starting to get to dry, they take action. The worker ants have two options at this point. The first one is to move the fungi to a chamber that has a higher humidity (Hölldobler & Wilson, 2011). This can be a long process and a waste of a chamber. The other option is to reconstruct (Hölldobler & Wilson, 2011). Sometimes, the dirt needs to be moved to make room for moister dirt and that will bring the humidity up. Sometimes reconstruction means tearing down, and/or building up tunnels to allow that chamber to have a higher humidity (Hölldobler & Wilson, 2011). This all depends on which tunnel the dry air is coming from.  Depending on the structure and the placement of the growing chamber involved, this is not always an option. The ants choose which one is best for their situation (Hölldobler & Wilson, 2011).




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