Worm-Root climbing behaviour: Insights from Active Polymer Simulations

California Blackworm (Lumbriculus variegatus) is a slender and flexible organism that lives in aquatic environments and is capable of tangling with one another to form an entangled structure. We investigate how this collective entanglement facilitates their interaction with plants and roots in their habitat. Using experiments with worms and duckweed, a free-floating plant found int the natural habitat of worm, we find that dangling roots of the duckweed provide support for maneuvering and entangling, which helps the worms climb. Drawing inspiration from this duckweed-worm assembly, we employ a coarse-grained computational framework in which the worm is modelled as a flexible active polymer endowed with self-propulsion and a chiral head motion, and the duckweed as a polymer of finite stiffness, either anchored or free at one end. Our simulations demonstrate that passive-polymer stiffness, intrinsic curvature of root tips and worm activity govern the climbing process. in a coordinated manner, inspiring bio-inspired robotic locomotion across diverse terrains. Our study shows how blackworms manipulate their environment in a coordinated manner, inspiring bio-inspired robotic locomotion across diverse terrains.