Data from: Collective strategy for obstacle navigation during cooperative transport by ants

Group cohesion and consensus have primarily been studied in the context of
discrete decisions, but some group tasks require making serial decisions
that build on one another. We examine such collective problem solving by
studying obstacle navigation during cooperative transport in ants. In
cooperative transport, ants work together to move a large object back to
their nest. We blocked cooperative transport groups of Paratrechina
longicornis with obstacles of varying complexity, analyzing groups'
trajectories to infer what kind of strategy the ants employed. Simple
strategies require little information, but more challenging, robust
strategies succeed with a wider range of obstacles. We found that
transport groups use a stochastic strategy that leads to efficient
navigation around simple obstacles, and still succeeds at difficult
obstacles. While groups navigating obstacles preferentially move directly
toward the nest, they change their behavior over time; the longer the ants
are obstructed, the more likely they are to move away from the nest. This
increases the chance of finding a path around the obstacle. Groups rapidly
changed directions and rarely stalled during navigation, indicating that
these ants maintain consensus even when the nest direction is blocked.
Although some decisions were aided by the arrival of new ants, at many key
points, direction changes were initiated within the group, with no
apparent external cause. This ant species is highly effective at
navigating complex environments, and implements a flexible strategy that
works for both simple and more complex obstacles.