Fact File

Of all the insects that cause harm in our daily life, perhaps the most commonly known are the fly and the mosquito. Let’s take this chance to do a bit of research into these two insects

Screen doors allow fresh air into rooms whilst keeping out mosquitoes and flies. Although they have been around for a long time, they are ideally suited to modern, ecologically sound lifestyles. The research undertaken by the Rolli International into the relationship between mosquito behaviour and screen doors is unique in that it has not parallels with any previous research carried out by an academic society. This website introduces part of the Rolli’s research, as well as information regarding mosquitoes and flies. This information alone should be helpful in bringing about a deeper understanding of harmful insects. Rolli intend to continue their scientific study into harmful insects like mosquitoes, enhancing our quality of life through the development of screen doors. I hope that these screens will be put into use by ecologically-minded future generations


There are about 20,000 species of wasp, including hornets and yellow jackets. Unprovoked wasp attacks are very rare. Wasps usually sting to subdue prey or in self-defense. People may be stung if wasps have been attracted to their food, or they have been attracted to their food, or they have inadvertently disturbed a nest. Unlike bees, wasps can sting repeatedly, however. A sting of a wasp can be very dangerous especially for small children and could even be fatal for some Wasps are attracted to light and warmth. They can easily get into even the smallest of openings but most of the time can’t get back out. Once stuck for a while wasps will become very aggressive increasing the chance of being stung. A good idea would be to take a cloth and cover the wasp and let it out back outside rather than killing it. But the best option would be not let them in altogether by installing ROLLI Roll-UP Fly Screens


The deadliest creature on earth, the anopheles mosquito, is responsible for more than 300 million cases of malaria each year, and causes between one and three million deaths. Malaria affects 10% of the world’s population, making it the leading mosquito-borne disease. Mosquito are most active at night Mosquito breed where there is abundance of still water, such as swamps or water tanks. Mosquito can easily find a way into even a slightly tilted window. Once they are in, the night can be considered sleepless. Not only do mosquito make an irritating sound when hovering above your ear, but they also bite. Even if the mosquito is not infected with some deadly disease, their bites hurt and itch afterwards. You can reduce the risk of being bitten by installing ROLLI Roll-UP Fly Screens


Houseflies can spread some 200 pathogens and parasites to humans. The tsetse fly is another dangerous variety, spreading sleeping sickness. Caused by a parasite, sleeping sickness enters the central nervous system where it causes deep coma and death. About 250,000 people die each year in Central Africa from sleeping sickness. You can reduce the risk of being a victim by installing ROLLI Roll-UP Fly Screens Apart from diseases, flies carry a lot dirt on their legs and wings. They aren’t the cleanest species on earth, so why would you let them spoil your meal at home? Keep flies out with ROLLI Roll-UP Fly Screens


Repellants, only mask you from the pesky mosquitos, and do not actually kill or keep them away. ROLLI fly screens prevent mosquitos from getting into your house altogether, so you won’t have to hear that mosquito noise ever again. Certain repellants actually harm the ozone layer of our earth, contributing to the problem of global warming The use of repellants can be harmful to people who suffer from breathing problems such as asthma, as this could pose problems for them. Repellants should not be used around plants or pets, as certain chemical elements found in repellents could pose a threat to plants and little pets. Installing ROLLI Fly Screens will save your health and money since you won’t need to use repellents


Blinds are commonly used to protect you from sun/glaring light and nosy prying eyes. The product casing is made out of aluminum and fitted with a blind canvas by your choice.(Shading %, blackout and design). A wide variety of blind canvases are available and samples can be provided on request Our blinds can be used and installed to almost any kind of existing Windows and Openings.Blinds are available in a wide range of RAL colors and will be an economic solution against heavy draw curtains Blinds can be easily and comfortable operated by hand with a ball chain or with a remote controlled motor device and stopped at any given point

  • Provides privacy and protection from sunlight and prying eyes
  • Economic solution to replace heavy curtains
  • Simpler to install than curtains
  • Adds elegance to any room
  • Easy operation by hand or remote control
  • Blinds can be positioned at any point. e.g.closed or as required
  • Easily serviced, maintained and cleaned
  • Can be easily installed onto any frame
The fabrics are environmentally friendly, control glare and are excellent for heat control. There are fabrics which allow you natural light and airflow whilst maintaining your view, translucent fabrics for filtered light, textured and full block out where required. Energy saving, excellent solar qualities plus protection for your furnishings adding years to the life of your carpets and furniture. The range and options plus the benefits go on and on The fabrics represent today’s fashion colours, providing a contemporary appeal that are durable and stable, with certain fabrics being fire retardant. The beaded chain control makes operation easy and all are fitted with cord retaining devices for child safety
    • Fabulous array of plain colours, prints, fabrics and trims
    • They are ideal with any decor scheme in any room
    • Fabrics are environmentally friendly, control glare and are excellent for heat control
    • Allow you natural light and airflow while maintaining your view.
    • Translucent fabrics for filtered light, textured and full block out where required
    • Energy saving, excellent solar qualities
    • They protect your carpets and furniture

Q: Are there all sorts of different mosquitoes? Do they all live by sucking blood from animals?

A: There are approximately 3200 species of mosquito in the world today. About 80 species carry diseases.
It is generally thought that all mosquitoes suck blood, however the truth is that a quarter of all mosquito varieties do not suck blood. What’s more, there is a widely held belief that the principal food source for mosquitoes is blood, however both males and females feed mainly on nectar from flowers. Blood from animals or humans serves as the nutrient source for maturing mosquito eggs, thus it is only the females that feed on blood.

Q:Why does it itch when bitten by a mosquito?

A: When mosquitoes bite people, they inject anesthetic agents and anti-clotting agents along with their saliva. When the saliva comes into contact with skin, it causes an allergic reaction, and this is the cause of the itchiness that occurs when we get bitten.

Q:I’m worried because there are so many mosquitoes near my house. What should I do? Where do you find large numbers of mosquitoes?

A: Well, first of all, let’s take a closer look at what sort of conditions are necessary for mosquitoes to live reproduce, and what sort of habitats they prefer.

Mosquito Ecology

Principal Breeding Grounds

A: Mosquitoes are often found in grassy places, bushes, and places where water collects. Drainage ditches, empty cans, old tyres, dark places, and places that have poor ventilation all provide ideal breeding grounds for mosquitoes. Other sources of mosquitoes include saucers under flowerpots on balconies and outdoor fishbowls.

Habitat and time of activity differ from species to species, however the important point is that they all lay eggs in places that have water. It's important to avoid creating any watery areas in places where there are already mosquitoes. This will prevent them from laying eggs. Buckets, empty cans, old tyres, and little pools of water in gardens can all provide suitable areas for mosquitoes to breed, so its important to make every effort to turn these objects upside-down and prevent water accumulating.
Although these things may seem like trivialities, it is possible to control mosquito outbreaks by following this advice.

A Primer on Harmful Insects

1. How are mosquitoes able to distinguish people?
Mosquitoes are capable of distinguishing between different colours, smells, and temperatures. In addition, they have compound eyes. Mosquitoes can only see things up to a distance of 30cm, however they are very perceptive of moving objects. If you wave your hand around to try to get rid of mosquitoes, this is effectively saying "I'm over here!". Aedes mosquitoes (striped mosquitoes) are active in the daytime, and are able to distinguish between 3 different colours. Mosquitoes like the colour black, thus will approach people who are wearing this colour. In addition, they are able to distinguish people by their breath, carbon dioxide released from their skin, and the smell of sweat. They can sense differences in temperature, and tend to approach people with a high body temperature.

2. What is the upper altitude limit that mosquitoes can fly to? What floor of a building can they get up to?
As mosquitoes cannot fly properly at wind speeds over 2m per second, they cannot fly up to the windy upper floors of buildings.
Having said this, they can ascend to the upper levels of a building by getting into elevators at the same time as people do, thus it is not possible to say that there will definitely be no mosquitoes on higher levels, no matter how high up the building you go.

3. What kind of people are prone to getting bitten by mosquitoes?
Mosquitoes sense carbon dioxide and sweat given off through people's skin, and home in on the source.
As they are capable of detecting tiny differences in carbon dioxide concentration, they are more likely to approach people who have even slightly higher levels of carbon dioxide secretion than normal.
After drinking, the level of carbon dioxide in breath increases, and this increases the likelihood of getting bitten.

Mosquitoes inject saliva when they suck blood. reaction, which in turn causes itchiness.

For people who are allergic to mosquitoes, this reaction can even result in death. Of all the damage caused by mosquitoes, the thing to pay most attention to is the range of infectious diseases that they carry. Mosquitoes inject viruses causing malaria, West Nile Fever, and other diseases along with their saliva.

West Nile Fever

West Nile Fever is an infectious disease caused by the West Nile Virus, and reports of outbreaks have traditionally come from Africa, Europe, and Western Asia.
In 1999, the previously outbreak-free United States had its first report of a West Nile Fever patient, and in 2003 there were almost 10,000 patients and over 260 fatalities.
West Nile Fever caught further public attention when it spread to Canada, with 1,100 patients and 10 fatalities.
Birds play host to West Nile Virus.


Of all the tropical diseases, malaria, an infectious disease caused by protozoa, causes the largest number of infections, with an estimated worldwide yearly infection count of between three hundred and five hundred million, and between one and a half and two point seven million deaths. The Hosts of Malarial Protozoa are Forest Inhabitants.



Dengue Fever

Dengue fever is caused by an infectious disease that is spread by a virus found widely distributed across the tropics and subtropics.
There are around one hundred thousand incidences of this disease every year. As the mosquito carriers of Dengue fever (Aedes aegypti, Aedes albopictus) are found in empty cans, bamboo stumps, and other areas where water gathers, they can be prevalent even within city limits.


Q: I've heard that flies are bad from a hygienic point of view. Why is this?

A: The answer to that question lies in the fly’s mode of life.
As you can see from the diagram below, flies grow to adulthood and feed in areas that are extremely unhygienic for humans. This means that their bodies, in particular their feet, are covered with pathogenic microbes.

Where Flies Live

GarbageDead Animal RemainsFeces

Fly Ecology

As flies feed and rest on food, excreta, rubbish and other unsanitary locations, they pick up and carry pathogens such as O-157 (E. Coli), as well as diseases of the skin and eyes. Some species, like Stomoxys calcitrans – the horn fly – also suck blood. Adulteration of food, drink, and other products in restaurants and food processing factories is currently a major problem.

Enterohemorrhagic E. coli (O-157)

O-157 is an enterohemorrhagic strain of the bacteria Escherichia coli, and is a cause of foodborne illness.
There was a massive outbreak of E. coli in 1982 in America, and successive outbreaks followed in North America, Europe and America, and Australia.
There are outbreaks every year in the summer.

Salmonella Food Poisoning

One of the major forms of food poisoning, salmonella food poisoning is caused by the salmonella bacterium, and is indicated by acute gastroenteritis. The principal carrier foods for the salmonella bacterium are beef, pork, chicken, and eggs, and in recent years there has been a marked increase in the incidence of salmonella-contaminated eggs. Bacteria are also found within eggs, thus special care is necessary.



Dysentery is an infectious disease that is found all over the world. It occurs with particularly high frequency in areas with low levels of hygiene. Many infection victims are people who have experience traveling overseas, although in recent years distribution of foodstuffs over a wide geographical area has meant that people who have never been abroad are also becoming infected.

Infectious Diseases Transmitted by Mosquitoes Infectious Diseases Transmitted by Flies
Disease Origin of Infection Disease Origin of Infection
Dengue Hemorrhagic Fever Aedes aegypti, Aedes albopictus , Other
Transmitted by bites from mosquitoes carrying the Dengue Fever Virus (Genus flavivirus, 1-4 types). Transmission does not occur through direct infection from person to person, only through a mosquito carrier.
Pathogenic E. Coli Bacteria O-157 Housefly (Musca domestica)
Carried by houseflies contaminated with O-157. Infection occurs through eating food infected with E. coli O-157 and through drinking water from wells that has not undergone sterilization.
Malaria Anopheles Mosquito
“Malaria” is the general term for disease that infects through bites from mosquitoes carrying malarial protozoa. Malaria is classed into 4 varieties depending on the malarial plasmodium involved – tertian malaria, quartan malaria, tropical malaria, and ovale malaria.
Salmonella Bacterium Cockroaches, Flies
Frequently occurs after eating cream-filled pastry cakes, fried eggs and other foods.
West Nile Fever (West Nile Encephalitis) Culex pipiens, Aedes aegypti, Other
West Nile Virus is transmitted by bites from infected mosquitoes. There is usually no direct person to person transmission. In nature, West Nile Virus is maintained through a cycle of infection between birds and mosquitoes.
Dysentery Bacillus Cockroaches, Flies
Infects through consumption of food or water contaminated with the dysentery bacillus.
Yellow Fever Polio
Japanese Encephalitis African Trypanosomiasis
African Trypanosomiasis ( Chagas Disease)
Visceral Leishmaniasis
Dermal Leishmaniasis
Mucocutaneous Leishmaniasis

Bee and wasp stings are common and painful. They are usually no more serious than this, but some people can develop a life-threatening illness.The most familiar sting is from honeybees, but some wasps and other insects can also sting. Yellow jacket wasps are the most common cause of allergic reactions to insect stings in the United States.

The bee's stinging apparatus consists of a sack of venom attached to a barbed stinger. The wasp's is similar, but with a smooth stinger. When a bee or wasp stings, the sac contracts, pumping venom into the tissue.

The information below refers to bee stings, but it applies to stings caused by both bees and wasps. The symptoms, treatments, and dangers are the same.

Fast facts on insect stings

Here are some key points about insect stings.

  • Bees, wasps, and other related insects can sting.
  • Pain and swelling are common symptoms, but these usually go away within a few days.
  • Bees leave a stinger that injects a toxic venom into the skin.
  • If a person develops swelling, hives, and breathing problems, they need immediate medical attention.


A bee sting is usually recognized by a sharp pain and a puncture wound or laceration in the skin.

The venom contained in a bee or wasp sting induces a local toxic reaction at the site of attack.

A normal local reaction to a bee or wasp sting produces the following symptoms:

  • instant pain at the site of the sting that is sharp, burning, and usually lasts a few seconds
  • a swollen red mark that can be itchy and painful
  • swollen and red hives or welts that may peak at around 48 hours after the sting and last for up to 1 week

Some stings may produce the following symptoms, referred to as a large local reaction:

  • extreme redness and swelling that enlarges up to 12 inches across
  • swelling of an entire extremity or limb, which may last a few days
  • in the case of multiple stings, there may be a rash, fever, nausea, and headache
  • rarely, swelling and pain in joints that appear after several days

Multiple stings can be fatal for children.

In some people, components of the venom can cause an allergic reaction.


Most reactions to a sting are mild to moderate and do not involve a severe allergy.

However, some symptoms that develop after a bee sting signal a severe allergic reaction and need urgent medical attention.

Without treatment, anaphylactic shock may occur very quickly. This can be fatal.

Symptoms that may signal anaphylaxis include:

  • wheezing or difficulty breathing
  • severe swelling of the face, throat, or lips
  • nausea, vomiting, or diarrhea
  • stomach cramps
  • itching or hives in places other than the site of the sting
  • fast heart rate
  • sudden drop in blood pressureor weak pulse
  • dizziness or feeling faint
  • difficulty swallowing
  • confusion, anxiety, or agitation

Insect repellents are Really Dangerous more than your expectation

Most Insect repellents contain DEET (N,N-diethyl-meta-toluamide) as their active ingredient. DEET is one of the few insect sprays (poisoners) that works to repel bugs. It is recommended for preventing diseases that mosquitos spread. Some of these are malaria, dengue fever, and West Nile virus.

But DEET is completely harmful for lungs and nervous system of the human body.

Other less effective insects sprays contain pyrethrins. Pyrethrins are a pesticide made from the chrysanthemum flower. It is generally considered nonpoisonous, but it can cause breathing problems if you breathe in large amounts.

Where Found

Insect Repellents are sold under various brand names.


Symptoms of using Insect Repellants vary, depending on what type of spray it is.

Symptoms of swallowing sprays that contain pyrethrins are:

  • Breathing difficulty
  • Coughing
  • Loss of alertness (stupor), from the blood oxygen level being out of balance
  • Tremors (if a large amount is swallowed)
  • Seizures (if a large amount is swallowed)
  • Upset stomach
  • Vomiting

Below are symptoms of using sprays that contain DEET in different parts of the body.


  • Temporary burning and redness, if DEET is sprayed into these parts of the body. Washing the area will usually make the symptoms go away. Burns to the eye may require medicine.


  • Low blood pressure
  • Very slow heartbeat


  • Insomnia and mood changes. These symptoms may occur with long-term use of large amounts of DEET (over 50% concentration).
  • Clumsiness when walking.
  • DEET is especially dangerous for small children. Seizures may occur in small children who regularly have DEET on their skin for long periods of time. Care should be taken to use only products that have smaller amounts of DEET. These products should be used only for short periods of time. Products containing DEET probably should not be used on infants.


  • Hives or mild skin redness and irritation. These symptoms are usually mild and will go away when the product is washed off the skin.
  • More severe skin reactions that include blistering, burning, and permanent scars of the skin. These symptoms may occur when someone uses products that contain a large amount of DEET over a long period of time. Military personnel or game wardens may use these types of products.


  • Moderate to severe stomach irritation
  • Nausea and vomiting 

By far, the most serious complication of DEET poisonings is damage to the nervous system. Death is possible for people who develop nervous system damage from DEET.


In recent years, there has been more and more concern about the importance of a healthy, energy-conscious lifestyle. Flyscreen help make this kind of lifestyle possible by harnessing natural breezes without causing any damage to the environment. Flyscreens are a necessity for every home, however, are they actually capable of preventing invasion by harmful insects?

We are using 18 × 16 fiberglass mesh for our screen.

Normal Experiment of Fiberglass Mesh 18×16

No Number of Mosquitoes Mosquitoes that Managed to Invade
1 41 0
2 43 0
3 40 0
4 42 0

Upon starting the experiment, we gathered mosquitoes in a box covered by Rolli Fly Screen and brought box near to human skin. The mosquitoes reached the mesh and clung to the mesh surface, however they were not able to pass through, thus they initially flew back, then again settled on the surface of the mesh. The experiment was carried out four times, and on no occasion did the mosquitoes pass through the mesh. It was clear from this experiment that, with the exception of cases in which there are rips or screens are left slightly open, it is not possible for mosquitoes to pass through the mesh, as mosquitoes do not attempt to enter by widening gaps in the mesh.

Features & Benefits

  • Rolli products are an ecological defense against all kind of insects/intruders and protect your family by creating an effective barrier between man and the environment.
  • Rolli products are ergonomically designed and come with our UNIQUE CLIP-ON SYSTEM for easy installation.
  • Rolli products are known for their ease of operation and their esthetic elegance that enhances the outlook of your home.
  • Rolli products are individually packed with EASY TO UNDERSTAND, STEP – BY – STEP DO IT YOURSELF Installation and operating instructions.
  • Rolli is the easiest, safest and cleanest way to keep your home and work place free from unwanted intruders.