Why do animals have so many receptors? The role of multiple chemosensors in animal perception

Many animals have an abundance and diverse assortment of peripheral sensors, both across and within sensory modalities. Multiple sensors offer many functional advantages to an animal's ability to perceive and respond to environmental signals. Advantages include extending the ability to detect and determine the spatial distribution of stimuli, improving the range and accuracy of discrimination among stimuli of different types and intensities, increasing behavioral sensitivity to stimuli, ensuring continued sensory capabilities when the probability of damage or other loss of function to some sensors is high, maintaining sensory function over the entire sensory surface during development and growth, and increasing the richness of behavioral output to sensory stimulation. In this paper, we use the crustacean chemosensory system as the primary example to discuss these functions of multiple sensors. These principles may be applicable to the function of autonomous robots and should be considered in their design.