"Their eyes are the animal world's equivalent of night-vision goggles ... it could be something glowing that you could eat; or it could be a potential mate. It's Russian roulette.

The presence of the tapetum can be observed at night when a pair of glowing eyes reflects back a flashlight or some other light source. (Interestingly, different animals have different color ...

Glowing animals are truly captivating, and they are one of nature’s more peculiar and stunning oddities. Many animals can glow in the dark. Fireflies famously blink on summer evenings.

Nocturnal geckos have superb vision in dim light - their eyes are 350 times more sensitive to colour at night than a human's (see for yourself with our animal vision interactive). Lacking eyelids, ...

they light up the night sky with their amazing bioluminescent ability. The main purpose of the glow is to attract mates. The humble jellyfish is perhaps the most bioluminescent animal on the planet.