Have you ever wondered why spiders seem not to care every time they see you from above their web?
They are just hanging there, not moving as if they cannot see or hear you enter the room. This leaves us to wonder – are spiders blind or deaf?
Spiders are not blind or deaf. Although spiders have very poor eyesight despite having extra pairs of eyes, they can still see you.
It is also amazing to know that they can hear the world around them even though they do not have ears – which is a prerequisite to hearing.
How Can Spiders Hear?
Spiders can hear sounds from more than six feet away. This is due to sensory organs on their legs.
The study was published in the Journal of Experimental Biology and confirmed that spiders can hear the high-frequency sound of high-pitched wings flapping. Sticking to their web, these eight-legged creatures can sense vibrations in the air.
They can also detect prey or predators from several meters away using their legs; scientists call this ability “spider-sense.” By determining the direction of the vibrations, they know if the danger is coming from above them or from the side.
Spiders Use Their Silk Web Antenna to Hear
While studying the acoustic properties of spider silk, researchers came across an interesting discovery: spiders can hear without ears.
They produce silk fibers and then instinctively produce a dish-like antenna. These silk fibers boast a unique acoustic quality that’s sensitive enough to pick up low-frequency vibrations.
The discovery may explain the arachnids’ ability to detect prey hidden beneath the water’s surface, using their silk, as a type of sonar. Spiders use their web to be able to “hear” sounds.
With the help of their web, they can extend their auditory ability up to 10,000 times larger than their body size.
Spiders Also Use their Legs to Hear
Unlike other insects and animals, spiders do not need ears to hear. They have a very unconventional way of hearing their surroundings, and that is by using their legs.
Yes, those eight long legs are not just for running because, in a way, it serves as their ears. A spider’s leg has hairs that can sense and act as receptors of vibrations from the web.
Read More: Do Spiders Know When You’re Looking At Them?
How Can Spiders Process Its Sense of Sight
When we think of a spider’s eyes, we see eight-round balls resting on top of their small head. But there are instances where you may see spiders with only six eyes arranged in a manner that experts can identify what type of species it belongs to just by looking at their eyes.
Spiders do not process their sense of sight as any other insect would. When you look at a spider, you will notice that it tilts its head while directly looking at you.
This is because spiders’ eyes cannot focus as they do not have a retina. Instead, each eye has a very thin cuticle that acts as the lens. In order for them to focus on something, they need to tilt their head to an angle.
What Do Spiders Use Their Eyes For?
As a kid, I often wondered why spiders have many eyes and what is the purpose of each eye. Spiders’ eyes are fixed, which means they cannot be moved from left to right or up and down. However, the lenses in their eyes can be shifted slightly for their vision.
According to experts, spiders use their front pair of eyes for hunting prey while they use the eyes on their side to see movement. It may be funny to think about, but this is a very important ability to sense any motion from their predators.
Different Spider Classifications and Their Sense of Sight
Most nocturnal hunting spiders have poor eyesight. Their ability to see is limited to differentiating light and dark shades.
Since hunting spiders have a strong sense of feeling vibrations, having a poor sense of sight is not an issue. Here are a few species of both nocturnal and daylight hunting spiders and how they see their prey.
The Tarantulas
Tarantulas are large hairy spiders with colors ranging from brown to black and can grow to more than 3 inches long as an adult.
Tarantulas spend their days under rocks while they can be seen hunting in the evening or late at night. Their diet may include crickets, caterpillars, or mealworms if they are kept as pets.
The Wolf Spider
Wolf-spiders belong to the family of nocturnal hunters, the Lycosidae. They are brown or black with long stripes on their body. Although wolf spiders are nocturnal hunters, they are often seen inside our homes by entering cracks or any other openings.
Do not worry if you may encounter a wolf spider, as they do not pose any harm to human beings. This type of spider also builds webs but only for sheltering purposes during the daytime.
The case is different from free-roaming spiders and day-light hunting spiders, which we see in trees, grass, and windowsill actively spinning their webs.
These types of spiders include net-casting spiders and flower spiders. They rely on their eyesight to capture prey rather than vibrations. Daylight hunting spiders need their ability to see from afar to be able to make a move on their target without being undetected.
The Net-Casting Spider
The Net-casting spider, also known as the ogre spider, has two large eyes located at the back of its head. The ogre spider’s eyes are fascinating, as new light-sensitive membranes are produced in the eyes every morning.
While the previous night’s membranes are destroyed. These eyes are perfect for tracking and netting their prey in low light.
Final Thoughts
Spiders are not blind or deaf. Rather they have poor eyesight compared to mammals and other animals. They use their web as an antenna to hear frequencies and feel the sound.
They also do not possess ears which are a primary requirement for one to be able to hear. Because of this, spiders rely on their legs with thousands of tiny hairs on their whole body to feel vibrations and sense movements around their environment.
