Most species of cockroaches love to emerge after the light goes out which makes them nocturnal. But it is nothing strange to spot a roach or two during the daytime as well. However, that is very rare.
The most times one spots cockroaches is when one turns on the light in a darkened room and immediately sees cockroaches scampering away to darker corners. This only proves that these insects are not very fond of light of any sort, whether natural or artificial.
Nevertheless, a cockroach is never good news and it does not matter whether you see them in the dark or during daytime. Therefore, it will do you good to have a basic idea about cockroach behavior to combat them better.
Are Roaches Attracted to Light or Dark?
Cockroaches like the dark because they can take cover from their natural predators such as lizards, birds, bees, animals, and humans. Years of evolution have turned them into such.
Anyplace wet and moist is preferred by cockroaches as they cannot tolerate sunlight. So, to answer the original question, most cockroaches are attracted to the dark.
The Asian cockroach, however, is different. Instead of being repelled by the light, they are attracted to it. They thrive in the outdoors and can be spotted in shaded and moist areas where they can feed on leaf litter.
However, they can also invade your homes and look for food, water, and light within. The Asian cockroach is capable of flying and so if you see a cockroach hovering near lamps or near TV screens then that is an Asian cockroach in all probabilities.
Will Sleeping With the Light On Keep Cockroaches Away?
Yes, sleeping with the light on is a clever idea to get rid of cockroaches. But it is hardly an effective or permanent one. Because cockroaches don’t come for the darkness, they come out for food and water.
As long as there is no sunlight, your artificial lighting won’t be in the cockroach’s way of nourishment for very long. The nights give them a good cover and with time they have evolved into creatures of the dark.
Instead of turning on the lights, you should remove their sources of nourishment to drive them away permanently. Before you go to sleep, you should do the following things to prevent a cockroach infestation in your home :
In the Kitchen:-
- Clean your kitchen thoroughly and make sure there is no food waste left around or even dirty dishes or utensils in the sink.
- Close the lid of the kitchen dustbin tightly. Take the trash outdoors if the place still smells after closing the lid.
- If possible, spray an essential oil-based cleanser or clean the kitchen with it.
In the Washroom:-
- Close the lid to sinks in the basin, the bathtub, and even the main drain. If there is no lid available, stuff a piece of cloth soaked in essential oil or garlic oil inside the drain holes.
- Make sure the washroom is dry and there is no spare water lying around. Cockroaches do not differentiate between clean and dirty water and will come for whatever is available.
- The washroom must be left clean, as in there should not be any waste lying around such as fallen hair, dirty underwear, toilet paper, nail clippings, etc.
- Keep the lid of the washroom tightly closed as well.
- Hang a mint or menthol-based room-freshening tablet in your washroom for added freshness and to keep cockroaches away.
In the Bedroom:-
- Try to limit eating in the bedroom to avoid littering the place with food crumbs.
- Make sure your pet is not defecating in or outside your bedroom.
- Seal up every possible entrance such as corners of window sills, with silicone or acoustic caulking.
- If you have a diffuser, use essential oil or citrus flavors in them as these are some of the smells that cockroaches hate.
Why Do Roaches Run From Light?
There is no biological reason why cockroaches must be away from light. But they still do. Ever wondered why? Well, to us humans who do not have to live in fear of being constantly hunted.
A little light may not mean much but for cockroaches, it is a different story altogether. These insects value being inconspicuous and do not come out unless they have to.
In the light, the chances of being spotted by predators larger than them are more, and thus they always carry on the important task of looking for food only when night arrives.
And in millions of years, since this strategy of avoiding light to survive has worked out well for them, they are now characteristically afraid of the light.
So it’s not like roaches are scared of the light because there is something in the light that harms them but rather they do so because of adaptation related to survival.
Why Do Roaches Hide in Dark Places?
Corners of the room, undersides of furniture, and such other dark areas are where cockroaches mostly gather.
At night, when there is no more illumination in their immediate vicinity, they emerge to feed themselves and go back right after. This is a survival tactic that they have learned through years of living.
If they hide in dark corners, then it is unlikely that they will be found by their predators. This is why you will see cockroaches scampering away the moment you turn lights on because the presence of light is equal to the presence of a threat to their lives for the roaches.
Can Roaches See in the Dark?
Cockroaches do have sight in the dark by using which they look for food and sense predators but it is not seeing as we understand. Cockroaches have eyes on the top of their heads which gives them a 360-degree compound vision.
But this vision is not clear as these insects also depend on their senses of smell and touch to detect food, water, and danger. The eyes are equipped with photoreceptor cells that do not completely focus on an object but rather enable the cockroach to sense its presence.
So, in a way, cockroaches can see without even looking at a thing and this sense of sight they have is applicable in each point of their 360-degree optical field.
Research conducted by a University in Finland deduced that each photoreceptor receives only one photon of light every ten seconds when light levels are extremely low. There is a pooling of light occurring in thousands of photoreceptor cells.
Their eyes are made up of around 2000 hexagonal units called ommatidium and through this, their nervous system receives a sort of neural signal when they come in contact with light.
Imagine touching a live wire with your bare hand. The feeling that you get is similar to what cockroaches feel when they come before light. They get a tiny shock in their nervous system which immediately makes them run away.
What Light Do Roaches Hate the Most?
Red-colored lights are known to be one of the most effective ones when dealing with cockroaches because they are repelled by them. This is because the colour red has the longest wavelength which makes it the most reflective.
It means that this color is perceived as very bright by cockroach photoreceptors which also send a signal to their nervous system.
In simple terms, the neural shock that roaches receive when they see red-colored light makes them associate it with extreme danger and they immediately try to take cover somewhere dark.
Therefore, it is clear that most cockroaches are not attracted to light and would prefer to stay away from it. The Asian cockroach however is an exception that is drawn to the light.
But evolution has given this species of cockroach wings so that they can protect themselves from their predators.
However, the rest of the cockroach species abhor light and would rather stay away from it for the sake of survival.