Abstract
Individual and colony ant behaviors, involving high sociability, chemical-based communication, swarming in search of food, the need for camouflage, and organization into mixed societies, can serve as inspiration for distributed systems. Collections of small robots are starting to implement some of these behaviors. This paper investigates the pros and cons of using these behaviors as the basis for a hypothetical robotic distributed house cleaning system.

---

Presented By:
Ken Webb

---

Introduction
his document reports on the pros and cons of using ant behaviors as inspiration for building a distributed robotic house cleaning system, tentatively called the KrumBum. This system must clean as well as a standard vacuum cleaner, by using a large number of autonomous micro-robots acting cooperatively in parallel. The initial prototype need only clean hard flat floor surfaces, but the final production version will also need to clean carpets. At pre- established times, such as the middle of the night, the KrumBum units will leave their nest. In as short a time as possible they will remove all the crumbs and dust from designated parts of the floor. They will carry the debris back to the nest for disposal. I will report on a sampling of potentially useful ant behaviors, will discuss several existing small robots that could possibly be adapted to implement these behaviors, will briefly compare ants and robots, and will discuss some reasons why it would be very difficult to use ants themselves as part of the KrumBum system and the implications of this for the use of collections of small robots.
Ants “ Individual and Colony Behaviors
A characteristic feature of all ant species is their high sociability. Ants are always found in colonies containing between a few hundred and several million individuals. In the view of Hölldobler and Wilson (1994, p.9) the competitive edge that led to the rise of the ants as a world-dominant group is their highly developed, self-sacrificial colonial existence. Working together within the colony, ants tend their young, defend themselves against other ants and insects, and cooperate to find food. If one ant leaves some task undone, another ant will almost certainly complete it. Some ants such as the Saharan desert ant Cataglyphis are solitary foragers (Wehner et al., 1996) but return to the colony nest with the food they find. At the other extreme are army ants that forage as a swarm and are never away from their nestmates. Under experimental conditions, when a group of a few thousand workers is cut off from the main swarm, the army ant social instinct is so strong that they will follow each other in a circular pattern. After 30 or more hours, this circular milling ends with the death of all the ants as they succumb to starvation (Schneirla, 1971). Ant species vary in their use of vision. The Cataglyphis desert ant has a sophisticated visual system that allows it to use landmarks for navigation while foraging away from the nest (Wehner, 1996). While all army ants have some sensitivity to light, many species have no eyes and use light only as a time-of-day signal (Schneirla, 1971, p.28-29). As for communication between ants using vision, not a single example has yet been solidly documented (Hölldobler & Wilson, 1990, p.259). Odor, the detection of pheromone and other chemicals, is the primary means by which ants distinguish between nestmates, food, and otherwise sense aspects of the environment. Ants also release a variety of chemicals in minute quantities from special glands. These chemical signals trigger response behaviors in other ants, which Hölldobler and Wilson (1990, p.227) have organized into twelve functional categories including alarm, simple attraction, recruitment, recognition, various group effects, and territorial marking. The desert ant is unable to use odor as part of its foraging behavior because the heat immediately evaporates any chemical (Lambrinos, 2000), and it must instead rely on vision. The army ant foraging pattern would not be possible in an open desert region (Schneirla, 1971, p.10). Chemical signaling is not point-to-point. One ant does not communicate directly with one other ant, in contrast with symbolic linguistic communication in humans. Instead, communication is through the environment. One or more ants release a chemical into the environment which may subsequently be detected by other ants or individuals of other species. If an individual is within range of a chemical signal diffusing through the air, and if it has a hard-wired behavior that is triggered by that signal (but dependent partly on other current environmental and internal brain states), that ant will engage in that behavior. In 1959 Grassé introduced the concept of stigmergy to explain a coordination paradox. Social insects appear to behave strictly as individuals, and yet somehow their individual actions result in complex global effects such as nest building and foraging patterns. Theraulaz and Bonabeau (1999) summarize the important principle of stigmergy as follows:

read full report
http://primordionpub/mscCoursework/AMI_ProjectReport_5.pdf