thigmotaxis

Thigmotaxis is a directional movement or orientation toward or away from a tactile stimulus or physical boundary. It is observed across animals and is studied in neuroethology and behavioral neuroscience. Positive thigmotaxis describes movement toward contact with a surface or staying near a boundary; negative thigmotaxis describes movement away from touch or into open space. In many experimental settings, thigmotaxis is used as a proxy for anxiety or risk assessment, particularly in rodents performing open-field or elevated-plus maze tasks, where animals preferentially stay near walls.

In invertebrates and some vertebrates, thigmotaxis supports navigation and stabilization in environments with varying textures or obstacles. Mechanistically, thigmotaxis is mediated by mechanosensory receptors that detect tactile stimuli, with initial transduction in peripheral sensory neurons and subsequent central processing to guide motor output. In nematodes such as Caenorhabditis elegans, touch-sensitive neurons and their signaling pathways contribute to edge-following behaviors. In mammals, skin and somatosensory pathways, as well as vestibular inputs, contribute to thigmotactic responses, which can be modulated by arousal and context.

Thigmotaxis is distinct from thigmotropism, which refers to growth responses to touch, rather than movement direction. Assessments of thigmotaxis are common in behavioral studies of anxiety, predation risk, exploration, and in studies of neural circuits underlying tactile sensation.