Worms navigate narrow paths faster than wide ones – these findings could inform robot design

Many creatures must navigate narrow pathways, such as worms burrowing through soil or aquatic organisms moving through tight spaces. Despite this, it is often assumed that wide, open spaces are easier to navigate than confined areas. However, recent research on California blackworms suggests that narrower paths can actually be faster for these creatures, with implications for robot design.

California blackworms, which are a few centimeters long, intertwine their bodies to form tangled bundles of threads or noodles. These worms often untangle themselves when they sense danger, such as ultraviolet light or an electric pulse. In the lab, researchers investigated how groups of worms behave when confined, leading to the question of whether computer simulations could capture the essential physics behind how these worms tangle together.

The researchers built a simple computational model using a flexible chain of beads that continuously pushes itself forward, mimicking the movement of a worm. Surprisingly, the simulation showed that the worm moved faster through a narrower channel compared to a wider one. This finding led to further investigation into whether this phenomenon held true for real worms.

To test this idea, the researchers designed experiments with real California blackworms in 12-centimeter-long channels, varying the widths from 1 to 8 millimeters. The results confirmed the simulation, showing that the worms consistently moved faster through the narrower channels than the wider ones. The confined space seemed to help keep the worms moving in a straight path.

The results of both the simulations and experiments were consistent, suggesting that narrower channels can be more efficient for California blackworms to navigate. This finding could have important implications for the design of specialized robots that need to move through tight spaces, such as in confined environments or small spaces.