Natures wonders: how ants handle obstacles in their way (Introduction)

by David Turell , Thursday, May 10, 2018, 19:22 (2387 days ago) @ David Turell

It turns out they have two methods and each individual ant plays its own role:

https://phys.org/news/2018-05-food-carrying-ants-problem-obstacles.html

"Ants working together to carry a large piece of food get around obstacles by switching between two types of motion: one that favors squeezing the morsel through a hole and another to seek a path around the barrier.

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"Ron and colleagues built a mathematical model that simulates ants' behavior when facing a rigid barrier with a narrow hole. The simulations suggest that ants randomly switch between two modes of motion, one in which they dwell near the hole, providing a chance to pass food through it, and another in which sideways motions allow them to seek their way around the obstacle. Switching between modes ensures the ants do not get stuck in a single mode without finding a solution.

"The model also predicts that the size of the food-carrying ant group, which reflects the size of the food item, determines which mode of motion will dominate. Small groups with smaller items will spend more time near the hole, while larger groups perform more sideways motions to get around the barrier. When encountering the obstacle each ant continues to behave according to the rules that govern their free, unhindered motion. Nevertheless, when encountering the obstacle these same rules give rise to the coexistence of the two observed motions that allow them to overcome the obstacle. In other words, the problem is "solved" by the collective without any of the individuals realizing the exact nature of the problem. (my bold)

"Study co-author Ofer Feinerman then led the testing of these model predictions in experiments with real ants carrying cargo that ranged from 1 cm to 4 cm in diameter. When the ants encountered a rigid barrier with a narrow hole, they did indeed switch between the two types of motion predicted by the model. Smaller groups carrying smaller items spent more time near the hole, as predicted."

Comment: Each ant follows his individual built-in rules, but the group as a whole is able to solve the problem