Have you ever wondered why spiders need so many eyes? Many spiders have eight eyes, but some have less than that. The factor that determined the number of eyes a spider has, as well as what each set of eyes is used for, is determined by evolution, the spider’s lifestyle and its hunting strategies.
The wolf spider has eight eyes all together. Four of its eyes sit in a row below two larger eyes, and the two remaining eyes are located one each on the sides of its head. So why not just have two eyes?
Each set of eyes often serve separate purposes. The wolf spider’s eyes that are located in the middle of the bottom row are meant for keeping track of polarizing sunlight in order to orient the spider with its surroundings. However, experts do not know what the wolf spider does with all of its other eyes, but it likely has something to do with gauging speed.
Researchers have determined that the outer two eyes on the bottom row of the wolf spider’s head are the most important. When these two eyes were covered, the wolf spider could not find its way home no matter how simple the path back to their nest was. Obviously there is still much research to be done on spider eyes, but at least now you know how to blind a wolf spider.
Have you ever placed yourself so close to a spider that you could make out all of its eyes? And if yes, how many eyes did you count?