Voles prefer familiar mates through olfactory sensory exploitation. Signs can communicate through any of the senses, visual, auditory, tactile, olfactory, or gustatory. Stimming behaviours can consist of tactile, visual, auditory, olfactory and vestibular stimming. These may include sensory, visual, psychic, autonomic, olfactory or motor phenomena. The island fox communicates using auditory, olfactory and visual signals. Signs can communicate through any of the senses, visual, auditory, tactile, olfactory, or taste. Crypsis can in principle involve visual, olfactory, or auditory camouflage. The amygdala participates in the hedonic or emotional processing of olfactory stimuli. Crypsis can involve visual, olfactory (with pheromones), or auditory concealment. There also have been pheromone receptor genes found in olfactory mucosa. It receives input from the olfactory bulb and olfactory cortex. This neural pathway differs from that used by the main olfactory system. Tubuloalveolar serous secreting glands lying in the lamina propria of the olfactory mucosa. Workers leave pheromones on these trails, which are detected by other nestmates through olfactory receptors. The disease begins in structures of the lower brainstem and the olfactory system.