hamatum responds to the environment in a particularly remarkable way: they spontaneously build bridges across impassable situations using their own bodies. As Gordon describes it, “A colony is analogous to a brain where there are lots of neurons, each of which can only do something very simple, but together the whole brain can think.” This shows that ants follow simple rules to flexibly respond to the available amount of food (they won’t send out more ants to forage if there’s nothing to find) without having access to information about the entire colony.
Research from the lab of Stanford University's Deborah Gordon, including a study by our own Bob Schafer, found that ants wait for successful foragers to return before sending out new foragers. Harvester ants live in the desert where pheromone trails wouldn't last in the dry heat, yet their colonies still take an intelligent approach to collecting food. In addition to pheromonal communication, individual ants use ‘rules of thumb’ to guide their immediate responses to circumstances. That’s why you’ll see more and more ants marching from the outdoors into your kitchen when there’s an available food source and ants nearby to find it. As other ants follow her back to the food source, more pheromones are dropped, thereby drawing more ants to the food trail. Most ants communicate through pheromones, particularly when scavenging for sustenance: a group of ants will sally forth in a haphazard manner to look for food and, when one finds it, she returns to the colony with a sample. But instead of eating the other species of ants they come across, they kidnap them and turn them into slaves who forage and raise the host colony’s young (Kronauer 54-59).Īll of the coordination involved in these various activities requires near-instantaneous communication, and for creatures who don’t vocalize, that requires some combination of instinct and adaptation. Like the Eciton burchellii, they descend upon other colonies en masse. The species Polyergus rufescens coordinate for a different purpose. Anchoring themselves to trees or logs, they hook their feet and mouths together, creating a sack for their fellow ants to live in, and thereby exposing only a fraction of the ants’ bodies to the elements (Kronauer 1-11). While many ants tunnel or create habitations out of plants and other materials, these army ants form bivouacs out of their own bodies. Feeding mainly on other arthropods-not newborn babies, as in Gabriel Garcia Marquez’s One Hundred Years of Solitude-, they gobble up whatever hasn’t gotten out of the way (including other ants), and when they’re done, they set up camp.
They will organize themselves into a uniform swath often tens of meters across and multiple meters deep, then move in unison. The army ants Eciton burchellii are nomadic, so a high level of coordination is necessary on a daily basis-every time they need to eat, they need to move. As Jurgen Kurths of the Potsdam Institute for Climate Impact Research puts it, “While the single ant is certainly not smart, the collective acts in a way that I’m tempted to call intelligent.”Ĭollective intelligence in animals accounts for the highly complex societies and behaviors of animals like, ants, birds, and fish, even when the collective’s individual animals may lack planning power on their own. It’s called “Viking horde or army ants?”Ī) Hundreds of thousands of these individuals were seen fanning out over the South American forest, devouring everything in their path.ī) These quickly depopulated dozens of villages in 9th century England.Ĭ) These show deference to a silent and immobile queen.ĭ) A popular novel ends when the heir to a family is brutally destroyed by these invaders.Į) This group is known for enslaving foreigners.Īnswers: a) army ants b) Viking horde c) army ants d) army ants e) both.Īs the game suggests, groups of ants and groups of humans don’t behave all that differently, despite being on opposite ends of the evolutionary tree.