Research

Gut bacteria coordinate through multiple overlapping communication channels rather than relying on a single signalling mechanism. A new review describes three major pathways: quorum sensing changes gene expression as bacterial population density changes; extracellular vesicles transport proteins, nucleic acids and signalling molecules between cells; and horizontal gene transfer distributes genetic capabilities through microbial communities.

Bacterial “zorbing” is a newly discovered form of collective social movement where spherical, biofilm-like microcolonies of Flavobacterium johnsoniae “walk” and migrate together across surfaces.

Collective animals can communicate indirectly through the fluid disturbances their own movements leave behind. This extends stigmergy beyond persistent structures such as ant pheromone trails or termite construction.

Bumble bee colonies can reorganise from a queen-centred hierarchy into a more decentralised social network when the queen disappears. Researchers tracked more than 80 million interactions in matched queenright and queenless Bombus impatiens colonies.

A minimal flocking model shows that a directional change initiated by one agent can propagate across an entire group at approximately constant speed through asymmetric local interactions alone.

Fish appear to switch communication channels according to how urgently their school is moving. Experiments with schools of 60 rummy-nose tetras found that fish with an intact lateral-line flow-sensing system responded to accelerating neighbours with about one-third less delay than fish whose lateral line was compromised.

A new framework proposes that moving animals can coordinate through the fluid disturbances they leave behind. Fish, birds, insects and microorganisms continually modify the water or air surrounding them, creating wakes, pressure gradients and other flow structures that neighbours can sense or exploit.

A theoretical study of collective escape proposes that animals can improve both speed and accuracy by treating an undisturbed neighbour as negative evidence about a possible threat.

To operate autonomously, minimal robot swarms must make timely and reliable collective decisions despite noisy individual sensing and severe constraints on communication, computation, and memory.

This study uses a conditioned escape response to follow how information propagates through schooling fish after selected individuals respond to a threat cue.