Without a doubt, cockroaches are one of the commonest pests in America households. There are in fact about 69 roach species found in America with a very high rate of reproductivity (a female can lay up to 10 – 90 eggs per time which hatch in days).
We all loathe the thought of having them as co-occupants, hence we generate high revenue for the pest control industry every year by buying their products in trying to exterminate them. In the day, roaches are rarely seen running around but at night is when they are most active.
They are special insects who can survive nine days without their heads because most of their nervous activities take place in nerve ganglia located throughout their bodies. Their love for the pitch black makes one ask how do they see.
How Do Roaches See?
Their Eye Structure
Roaches are very amazing creatures. As pesky as they are, they have some optical features scientists are probably researching on how to adapt to human visual aids. Unlike humans and most mammals, they have their eyes on their head which enables them to have a 360-degree vision of what goes on in their environment.
They do not see objects clearly by focusing on them. Their compound eyes are used to detect movements within their optical fields. This sensory ability is what enables them to run away from predators without necessarily having to see them. They see every movement as a threat and they are very good at hiding.
Their compound eyes are dorsolaterally situated on the head. They are black and bean-shaped made up of about 2000 hexagonal units called the ommatidium. Each unit functions as a visual receptor.
Can Cockroaches See in the Dark?
Research has proven that cockroaches see in the dark by being able to pool light signals over time. Through the ommatidium, the nervous system of the roach accumulates electrical neural signals summing them up to see in the dark.
Uses of the Antenna
With its pair of antenna, a roach has a sixth sense with which it interacts with the environment. Each antenna is as long as the body and it contains tiny hairs called bristles. On these bristles are mechanoreceptors which convey tactile and active sensory signals.
They allow the roach to detect vibrations caused by the movements of other creatures in the environment. Through this, the roach is able to sense the presence of a predator.
Another function of the antenna is that it allows the roach to smell the chemical components of the atmosphere. It works like an olfactory nerve. The roach then locates food by sensing the environment with the antenna.
A male cockroach uses the antenna to detect a female cockroach on the heat. This then leads to courting and eventually to mating.
They are afraid of the light which is why when they are not hunting for food, they hide in the dark at daytime. They see light as a threat. A roach will serve as a good meal to quite a number of animals. Their nocturnal nature is thus a good way of hiding from predators.
Also, their nocturnal nature is the reason they are able to feed on the things we eat when we sleep. This is why proper storage of food items is strongly advised. Roaches are one of the fastest insects in the world able to move in the dark with an average speed of 3mps.