Random behaviour, amplification processes and number of participants: How they contribute to the foraging properties of ants

Abstract

Two major types of foraging organisation in ants are described and compared, being illustrated with experimental data and mathematical models.The first concerns large colonies of identical, unspecialised foragers. The communication and interaction between foragers and their randomness generates collective and efficient structures. The second concerns small societies of deterministic and speeialised foragers, rarely communicating together.The first organisation is discussed in relation to the different recruitment mechanisms, trail-following error, quality and degree of aggregation of food-sources, and territorial marking, and is the key to many types of collective behaviour in social insects. The second is discussed in relation to spatial specialisation, foraging density, individual learning and genetic programming. The two organisations may be associated in the same colony.The choice of organisation is discussed in relation to colony size and size and predictability of food sources.

Effects of social group size on information transfer and task allocation

“…Deneubourg et al, 1986Deneubourg et al, , 1990Deneubourg and Goss, 1989) have investigated models similar to Equation A8 but that have unstable internal equilibria and simultaneously stable boundary equilibria. In these models, a trail's attractiveness to potential recruits increases faster than linearly with the pheromonal concentration on the trail.…”

“…Most of this work explores how individuals are allocated to different components of a single task, including the allocation of foragers to food sources that differ in quality (Seeley et al, 1991) or to food sources in different locations (Deneubourg et al, 1986;Pasteels et al, 1987;Deneubourg and Goss, 1989) or the allocation of workers to various aspects of nest construction (Jeanne, 1986). Other studies model how individuals are allocated to a variety of different tasks .…”

Colony Size, Communication andAnt Foraging Strategy

“…This paper aims to verify a prediction of the following hypothesis (Pasteels et al 1985;Deneubourg et al 1986). In theory, the organization of a small insect society can rely on most individuals at any moment "knowing", principally by learning, what it must do, where it must go, etc., and the workers' behavior has a strong determinist component.…”

The response of foraging Argentine ants, Linepithema humile, to disturbance

“…The quantity of pheromone a worker adds to a pheromone trail varies with the nutritional state of the colony and increases with the quality of available food. A slight increase in the quantity of pheromone voided per worker can lead to a large increase in the number of ants recruited to a food source (Wilson 1962(Wilson , 1971Deneubourg et al 1986;Breed et al 1987;Hölldobler and Wilson 1990). As the food source becomes crowded or the colony approaches satiety, the probability that an individual will add to the pheromone trail declines, causing a reduction in the recruitment of workers.…”