Olfactory Basis of Homing Behavior in the Giant Garden Slug, Limax maximus

Time lapse photography of slugs living in an experimental enclosure shows that these animals can return to a homesite from over 90 cm by a direct route. Slime trail following and vision are not involved in this behavior. In the presence of a low velocity wind, homing occurs upwind. Surgical disconnection of the presumptive olfactory apparatus (digitate ganglion) from the central nervous system eliminates homing. Neurophysiological recordings from the receptor surface associated with the digitate ganglion and the olfactory nerve demonstrate the olfactory function of the digitate ganglion. The olfactory acuity and capacity for directed locomotion via olfactory cues are also relevant to studies of slug feeding behavior, ecology, and learning ability.