Ant Lessons
The following Chapel Talk was given by Upper School Mathematics Teacher David Lane in the fall of 2022 .
I
learned something jaw-dropping this past weekend . I learned how many ants there are on Earth : For every individual human being on this planet , there are two-and-a-half million ants . I have a hard time imagining what two-and-a-half million ants look like , let alone two-and-a-half million per human being on the planet . These staggering numbers got me thinking about these creatures , and today I would like to share with you some of the incredible feats these animals are capable of performing .
Ants seem like simple creatures , but as a colony , they are one of the most successful organisms on the planet . One species of ant , the Argentine ant , has colonies today that are larger than some human civilizations , covering vast swathes of different countries . In fact , research suggests that many of these supercolonies are parts of a single megacolony that spans three continents !
Despite being individually fairly simple , in groups , ants are capable of complex behavior that enables them to be so successful . For example , army ants will build bridges out of their own bodies to help the rest of the colony cross a gap : They anchor their limbs to each other to create a new path . However , there isn ’ t an ant giving directions , no ant who directs the others by saying , “ Ok , everyone line up ; we ’ re building a bridge ! First ant , wait here . Next ant , you line up here , and so on .” An ant ’ s brain isn ’ t even complex enough to know that it is building a bridge , let alone to understand what the rest of the colony needs .
This is not the only complex task that ant colonies are capable of executing . They are also known to be able to adapt to different conditions around them , such as an invasion by another colony . To do this , some ants switch tasks they are assigned to perform within the colony , from roles such as caring for the queen or gathering , to fighting the invaders . Again , there ’ s no ant commander who examines the colony ’ s situation and tells the other ants what they need to do .
So , how is it possible for ants to be able to build bridges when they cannot understand what a bridge is , or understand what their colony needs ? And how can ants respond to threats by changing their behavior when they cannot tell what is happening across the whole colony ?
The key is that small , simple actions can create remarkable effects when they are combined with other small , simple actions .
Ants can build a bridge with just two rules . Rule one : Freeze in place if someone climbs over you . Rule two : Slow down if you reach a gap . Imagine this from the perspective of an ant at the front of the line of ants . It reaches a gap in the path , so it follows rule two and slows down . There is a whole crowd of ants marching behind it , though , still moving at full speed . So , they push forward and start climbing over the first ant . The first ant responds by following rule one : It freezes in place . The marching ants continue to climb over this frozen ant , until the one leading the march gets to the far end of the ant it is climbing upon . It reaches a gap at the far end , so it slows down . The ants behind it continue to push forward , and it too gets climbed upon . In response , it also follows rule one and freezes in place , allowing the ants behind it to climb over it as well . This process repeats until a string of ants make a tangled bridge , all frozen since they were climbed upon by the rest of the marching ants !
With the bridge complete , the remainder of the colony can continue marching . The ants in the bridge stay there until another rule tells them how to disassemble their bridge . Rule three states that an ant should begin moving again once a certain amount of time has passed without it being climbed upon . So , after the colony crosses the bridge , the very first ant that comes to a stop notices that it has not been climbed over for a bit , and starts to move again , climbing over the remainder of the bridge . The others in the bridge stay in place for a little longer , since they ’ re being climbed over by this ant . Then , the second ant follows suit , climbing over the remainder of the bridge . This pattern repeats until all the ants have crossed and the bridge has been disassembled .
So , three small , simple actions that each ant takes allow the colony to create something as complex and valuable to the colony as a bridge .
The same pattern allows some ant species to rapidly respond to invasions from another colony . In these species , each ant leaves a little chemical trace behind where it walks . Ants can also sense the chemicals that others have left . The chemical is determined by what job the ant does in the colony . For example , soldiers leave one chemical , workers leave a different one . The ants follow one
24 • Saint David ’ s Magazine