Not only does a spider have eight legs, but many spiders also have eight eyes. While all those eyes may seem like a superpower, spider vision isn’t as strong as you might think. You’re more likely to spot a spider in a dark environment, but can spiders actually see in the dark?
Read on to learn more about spider eyes and how arachnids navigate the world around them.
Can Spiders See In the Dark?
Even though most spiders have eight eyes, they tend to have poor vision. While spiders can typically see well enough to detect movement when it’s bright, it’s not possible to do that in the dark. Spiders have to rely on other senses, like hearing, smell, and taste, to find prey and detect threats.
Most spiders can’t see well whether it’s dark or light, but there are a few species with excellent eyesight. Net-casting spiders have two large eyes near the back of their head that function as built-in night goggles! Wolf spiders hunt nocturnally and can actually see more clearly in the dark.
There are also some spiders that are completely blind. Some cave-dwelling spiders, like the Kauai cave wolf spider and the eyeless huntsman spider, are born without eyes at all. Spiders have many ways to sense the world around them, and not every species needs to be able to see in the dark.
Why Do Spiders Like the Dark?
Since many spiders can’t see in the dark, you might expect them to seek out sources of light. However, the opposite is actually true. Spiders have a strong preference for dark environments and tend to avoid bright lights.
Many spiders are nocturnal and more active at night. For a spider, bright environments can be dangerous. Light can help a spider to see, but it can also help animals that feed on spiders spot their prey.
Spiders have many natural predators, and wandering into the light could be fatal for these arachnids. Darkness can help spiders to hide from predators and stay safe. When a spider is in the dark, it can also rely on its other, more powerful senses and protect itself from potential threats.
Spiders don’t rely on their vision, and dark environments are safer for spiders even when they can’t see.
Do Spiders Have Good Hearing?
Even though spiders don’t have ears, they’re still capable of detecting sound. Their bodies are covered in long, thin hairs that it can use to detect air movement and vibrations. A spider’s internal nerve receptors provide it with additional information about the movement and position of creatures around them.
Some types of spider, like the ogre-faced spider, also have nerve receptors on their legs. These receptors are able to detect both low and high frequency soundwaves. Thanks to its strong sense of hearing, the ogre-faced spider is able to hear sounds from up to six feet away.
Spiders also have a strong sense of taste and smell. Instead of relying on its nose, a spider uses the sensory organs on its leg to pick up scents. A spider can use its sense of smell to find food and potential mates. Smells can also help spiders detect threats, and spiders are known to avoid certain scents, like citrus and peppermint.
Can a Spider See Colors?
Many spiders have dichromatic vision, which allows them to green and ultraviolet colors. In comparison, humans typically have trichromatic vision and are able to perceive green, blue, and red. Spiders are sensitive to light and are able to see some colors, but there are many colors that a spider can’t detect.
A spider is able to see through all of its eyes, but these eyes don’t all see in the same way. Spiders have larger primary eyes that see images and smaller secondary eyes that it uses to track movement and distance. While a spider’s primary eyes have limited color vision, most spiders can’t see color with their secondary eyes.
It can be difficult for a spider to distinguish between certain colors, but that doesn’t mean it sees the world in black and white. Researchers have found that spiders are more likely to respond to color videos than footage in grayscale. Since spiders are usually most sensitive to light on the green spectrum, they’re also drawn to the color green.
There are also spiders that have full color vision. Jumping spiders can see in three color channels and can even perceive colors that humans can’t. It’s common to find colorful patterns on the bodies of male jumping spiders, which they use to attract mates.
Having eight eyes doesn’t necessarily help spiders see. Lots of spiders have poor eyesight, especially in the dark. While jumping spiders can see more colors than humans can, many other species of spider are virtually colorblind.
Thankfully, a spider doesn’t need eyes to see. Not only are spiders very sensitive to vibrations, but spiders can use other senses, like smell, taste, and touch, to gather information. This means that spiders can thrive in the dark even when they can’t see.