All Out War Between Alien Nations
The ants determine friend or foe by scent. Three other large nations exist in CA. When Argentine ants of different colonies (different scent) come into contact with one another, war commences, and it continues on a scale that puts even human killing to shame. This is because their nations or colonies are the most vast of any ant societies. When two such huge social orders have bellicose encounters, yet with no retreat on either side, they simply continue fighting and dying for decades. Two Argentine ant nations in CA are thought to have been literally tearing one another apart for about a hundred years, with no apparent letup on the horizon. Their fronts are miles in length. Measured in human dimensions, it would translate to hundreds or thousands of miles of unceasing combat. Each month sees the gruesome death of millions of their individuals, yet each month millions more march into the fray.
Our own species at least can form treaties, sign armistices, sue for peace, etc., and so take breaks of a generation or so from intense warfare. After the example of the Argentine ant, then, we are but the second most deadly creature on the planet. Nonetheless, we keep devising new and more efficient or heartless ways to kill one another. In time, we may surpass even this tiny competitor's morbid record.
Although most of us, even if we live in CA, may be unaware of Argentine ants, they are making a difference for humans. Their aggressiveness is not just toward their own kind but also is directed at other ants and insects, many of which are native, are part of the original ecosystem, and are what we would consider beneficial, insects that help with soil cultivation, seed dispersal, and so on. So, just as other areas are having problems due to too few sugar bee colonies, CA has a difficulty with too few ant and other insect species, thanks to the enormous range and aggressiveness of these Argentine ants.
Human efforts to eradicate them have so far been unsuccessful. They have colonies not only in CA and, of course, Argentina, but also in New Zealand, Europe (where a single colony stretches for hundreds of miles along one coast) parts of Africa, etc. It is thought that, when we are finally able to get a handle on the problem, it will be by manipulating the ants' scent or scent recognition, making them think friends are foes or vice versa.
Though it is not to our advantage that these insects resolve their tendencies toward intense intra-species combat, in a way, humans and Argentine ants share a common challenge, acquiring a less nationalistic and a more global sense of personal identity. Loyalty to one's tribe, colony, nation, or race may have been all well and good when there were relatively few of us around or we were isolated geographically and perhaps had to compete in smaller areas for the local resources. Now that we have dispersed around the sphere and in many cases have abundant energy and food supplies, such often lethal antagonism is inefficient at best and dangerous for our overall survival at worst. Are we better in this regard than Argentine ants? The jury is still out.
Primary Sources: Tracking A Sisterhood Of Traveling Ants. Dave Davies (host, filling in for Terry Gross), interviewing Mark Moffett on Fresh Air - National Public Radio, which aired on 6/17/2010;
Mark W. Moffett, Adventures Among Ants: A Global Safari With A Cast of Trillions (University of California Press, 2010).