When you see something it’s because visible light is being reflected off of an object.
There are other wavelengths of light that aren’t visible to us, like infrared and ultraviolet.
Spiders are made of something that is able to reflect ultraviolet radiation.
It doesn’t have anything to do with humans.
It could help them keep birds away because bright flashy colors usually means that the animal is poisonous. (Birds can see ultraviolet light)
Latest Answers