Despite the complex nature of dendritic aborizations, the dendrites of a single neuron rarely touch. Cell surface proteins have been implicated in this self-avoidance phenomenon, but other molecular determinants have remained unclear. Here, the authors showed that in Caenorhabditis elegans, disruption of netrin (UNC-6) signalling led to a failure of touch withdrawal in dendrites of PVD nociceptive neurons, as revealed by time-lapse imaging. As netrin is a diffusible factor that is involved in axon guidance, this study shows that dendrite self-avoidance may be achieved through various strategies.