Cockroaches seem to have a sixth sense when it comes to escaping threats. Have you ever noticed how difficult it is to find a cockroach in your room after it ran to hide? So how are roaches so good at detecting movement and escaping? What kind of eyes to they have? Are they blind?
No, cockroaches are not blind. They have a pair of compound eyes which do not provide sharp vision like human eyes, so they do not have clear vision of objects. But what a roaches eyes are very good at is detecting the movement of objects in their field of vision.
This makes sense if you consider that roaches are not hunters and don’t need sharp eyes to focus on their prey. They eat food that is stationary, such as dead animals and plants. So the blurry vision from their compound eyes works just fine for this endeavor.
Cockroach eyes are fine tuned to detect movement
What is more important to the cockroaches survival is being able to detect predators in its environment. Many animals will feed on cockroaches and that is why roaches are nocturnal animals and tend to hide when they are not out looking for food. As you have probably experienced, cockroaches scatter when a person enters the room. This is a defense mechanism that is well-suited to their survival.
Anything that moves is a potential threat to the cockroach. So their eyes are more attuned to detecting movement than to focusing on various objects. Once they detect motion, they will run towards dark areas and places where they can cover and hide.
Night vision is no problem for a cockroach
Cockroach eyes are also well equipped to operate efficiently in dim light or darkness, which comes in handy these nocturnal creatures. Cockroaches are avoidant of light, and prefer to stay in the dark. That is because their version of night vision makes it easy to navigate in the dark. It gives them survival advantages over other animals operating at night.
Cockroaches also have wraparound eyes which provide for 360° of vision. Since there is no blind spot, as it were, it is impossible for a predator to sneak up on a cockroach unless it is sleeping.
Roaches are not “third eye blind”, either
In addition to their eyesight, cockroaches have several other ways of “seeing” that they are also heavily reliant on. For example, roaches have a pair of antenna on their head which are used as fine tuned sensors. Each antenna has tiny hair-like bristles which are very sensitive to minute air vibrations set off by the movement of other animals it in its environment. In this way, roaches can detect other living things around them based on vibrations caused by their movements.
The antenna can also detect chemicals in the air, which helps the cockroach to “smell” its environment. This is helpful for locating food, predators, and exploring its surroundings. So, not only do cockroaches use their eyes to see, they also use these antenna as a secondary set of “eyes” with which to see.