Darwin IV - Senses

Senses

The species on Darwin have all evolved sonar, echo-location using a variety of sounds as their primary sense, rather than perceiving light, as most animals on Earth do. Many have complicated cephalons to aid in this sense. The majority have also evolved biolights; but rather than communicating information in the visible light spectrum, biolights on Darwin IV function in the infrared range, as all Darwinian animals are quite sensitive to that spectrum. It is important to note that their sensory organs to detect light in the infrared spectrum are more comparable to thermoreceptors found in pit vipers or rattlesnakes. The Rimerunner still has one bizarre, retractable, atrophying eye, a remnant from a time when sight-based organisms still had a place on Darwin IV. Also, most species are hermaphrodites.