Top 15 Most Interesting Facts About Flies

When people see a fly, they often assume the area is unsanitary. Flies are known carriers of diseases because they feed on human and animal waste, decaying bodies, and garbage. They are also a nuisance, with some species capable of biting and posing serious health risks. For instance, houseflies, commonly found in human dwellings, can spread various diseases such as Salmonella and diarrhea.

Flies transmit diseases due to their eating and breeding habits. Bacteria from their food sources stick to their mouthparts and legs, spreading germs wherever they land. Imagine leaving food uncovered and attracting flies. Flies belong to the Diptera order (from the Greek words 'di' meaning 'two' and 'pteron' meaning 'wing'), with one pair of wings on the middle thorax and a pair of balancing organs on the rear thorax. Some flies, like those in the Hippoboscoidea family, are wingless.

However, there are simple ways to identify the signs of a fly infestation and take preventive measures, as flies can become a serious problem if left unchecked. The Diptera order includes over 240,000 species, including mosquitoes, blowflies, and others, although only about half have been studied. This order plays an important ecological role and is significant in human health and medicine.

Maggots are the early stage of a fly's life, also known as larvae. Certain types of maggots found on dead bodies are valuable to forensic investigators. By studying their development, experts can determine the time and location of death. A typical maggot measures between 10-20 mm in length. During the hot summer months, a fly's lifecycle lasts about 12–14 days.

Maggots are also bred for commercial purposes, such as fishing bait, feed for carnivorous animals like reptiles and birds, or even used in familiar beneficial species like the blowfly. Due to their increasing popularity, maggot vending machines have been installed in Northampton, England.

While many maggot species cause damage to crops and livestock due to their parasitic lifestyle, some are also used in medicine and food production, particularly in cheese making.

The strangest maggot species known is the mouse-tail maggot. It can survive in polluted environments, and its body has a long tube that floats on the surface of water for breathing.

To fully develop into an adult fly that flutters around, a fly must undergo four distinct life stages: Egg – Larva – Pupa – Adult Fly. The duration of each stage may vary depending on the species of fly. Taking the common housefly as an example, its lifecycle progresses through four specific phases:

Egg Stage:

• The female fly, after mating, will find the most suitable place to lay her eggs.
• The eggs are white, approximately 1.2mm in size.
• These locations are chosen because they provide an ideal environment for the larvae to thrive.
• The eggs are typically laid in filthy places like animal carcasses or trash.
• Each time she lays eggs, a female fly can produce 75 – 150 eggs, with the total number of eggs laid in her lifetime ranging from 500 to 900.

Larval Stage (Maggot):

• The maggots in this stage measure between 3 – 9mm and will molt twice as their bodies grow.
• The larvae hatch from the eggs in 1 – 3 days and are known as maggots.
• After hatching, they consume surrounding organic matter to absorb proteins and nutrients, staying at the egg-laying site.
• The main task of maggots is to feed and build energy, eventually seeking a dark place to prepare for the pupal stage.

Pupal Stage:

• At this stage, the maggots find a dry, cool, and dark environment to continue their development.
• The pupa begins pale yellow, darkens over time, and finally turns reddish-brown.
• After storing energy for 2 weeks to a month, the larvae transform into pupae.
• In reality, the pupa is a cocoon containing a larvae evolving into a fly.
• Pupae are cylindrical, with a rounded head and a shell that gradually hardens, reaching about 1.2mm in length.

Adult Fly Stage:

• The pupa transforms into an adult fly in just 2 – 6 days under ideal conditions, and about 20 days under poor weather conditions.
• The development time for males is about 16 hours, while females take 24 hours.
• The adult fly breaks free from its pupal shell, measuring 5 – 8mm in size.
• It then flies around in search of food and to lay eggs, continuing the cycle.
• As adults, flies only live for about 14 days, but they produce thousands of eggs, so their population grows rapidly.
• The average lifespan of a housefly is about 28 days, including the egg stage.
• Flies consume all types of food, including human and animal waste, especially infectious waste like saliva, vomit, feces, blood, and necrotic tissue.

Though small, the fly's eyes have a complex structure that allows them to see the world with a broader field of vision than humans. Hidden within their eyes are thousands of intricate lenses that form a sophisticated visual system, enabling flies to observe their surroundings with remarkable detail. Let's take a closer look at how these pests perceive the world.

Have you ever wondered why swatting a fly is so difficult? The eyes are a gift from nature to flies. They possess compound eyes made up of thousands of visual receptors. Each lens operates independently to create a wide, mosaic-like image, which allows flies to detect even the slightest movements within a large area.

Despite having nearly 360° vision, flies' eyesight isn't very sharp. This is because their eyes are immobile, and they lack a pupil to control the amount of light entering, meaning they cannot focus on objects at various distances and can only see up to a few meters away. The fly's vision is clearest when observing the mosaic pattern formed by the small lenses, or ommatidia, which send the gathered images to the fly's brain to create a cohesive picture.

Additionally, flies are limited in their ability to perceive colors. They only have two types of color receptors, making it difficult for them to distinguish between white and yellow and completely unable to see the color red.

According to Analytical Chemistry, the larvae of certain fly species that inhabit corpses have long been used in forensic science to determine the time and circumstances of death. It is known that even experienced forensic entomologists cannot always confidently identify a fly species from its larvae. For some species, this is impossible, and investigators must wait for the fly to mature from its larval stage before it can be identified more easily.

This delay can result in the loss of valuable investigative time. Additionally, DNA analysis is not always a reliable method for identifying the fly species, as the genetic profiles of many fly species have yet to be discovered.

Recently, a team of chemists from New York University, led by Rabi A. Musah, developed a new method for identifying fly larvae. They gathered molecular data on the larvae using high-precision mass spectroscopy and discovered that different fly species have distinct molecular compositions in their larvae.

In their tests, they successfully identified larvae from six fly species: Calliphora Abbeyina, Chrysomya rufifacy, Lucilia coeruleiviridis, L. sericata, Phormia regina, and Phoridae. This breakthrough provides forensic experts with a valuable new tool for investigations.

When a fly is frightened or in an emergency, it exhibits an extraordinary reaction. The fly will flutter its wings, tilt its body, and spin mid-air like a tiny fighter jet, moving at an astonishing speed—faster than the blink of an eye.

In a study published in *Science*, scientists revealed that flies have a unique 'sensor' system, helping them avoid obstacles during flight.

Researchers used three high-speed cameras to track and analyze the fly's movements in various scenarios. The results showed that under normal conditions, the fly's wingbeat rate is around 200 beats per second. However, when threatened, it can rapidly accelerate and change direction in just 1/100th of a second—50 times faster than the blink of a human eye.

Even though the fly's brain is as small as a grain of salt, it functions as a complex system, similar to the brains of larger animals like mice.

Additionally, the fruit fly, scientifically known as Drosophila hydei, is as small as a sesame seed but has an extraordinary visual system—a 'guardian angel' that helps it survive in a world full of predators. Its brain is intricately structured, allowing it to quickly detect danger and find an escape route.

Known for being one of the dirtiest insects, flies are particularly attracted to filth. Thanks to their keen antennae, they can quickly locate their favorite spots. Flies breed in rotting organic matter full of bacteria, and when they land on food, they spread over 65 types of diseases.

Since flies often land on filthy surfaces, their feet are covered in hundreds of bacteria. This is why, when they land on food, they transfer harmful germs that can indirectly cause diseases in humans, such as food poisoning, diarrhea, cholera, and typhoid.

Musca domestica, commonly known as the house fly, is one of the most common insects worldwide that spreads bacteria and affects health. These flies carry decaying organic waste, including animal carcasses and feces, from their surroundings. After laying eggs, maggots hatch, grow into larvae, and eventually mature into adult flies within a few days. These flies can live for up to a month and lay hundreds of eggs.

Infection risks arise when flies land on food. House flies lack teeth and feed by sucking liquids through their proboscis, similar to a straw. For solid food, they regurgitate saliva to liquefy it, making it easier to ingest.

House flies are major carriers of diseases and can infest any type of home. They are attracted to all types of food, including human food, pet food, livestock feed, food waste, and even feces. Spotting adult flies is the most common sign of their presence and a potential health risk. Maggots are also visible when they crawl out from breeding sites to develop into pupae.

Adult flies range from 5-8 mm in length. Their thorax is gray with four small stripes, and their abdomen is either light brown or yellow. Their body is covered in tiny hairs, which serve as sensory organs. With complex compound eyes containing thousands of lenses, flies have a wide field of vision. The fourth wing vein is curved, and the wing tips are slightly pointed. Maggots are white and taper to a pointed end, with two breathing pores located at the rear. They have no legs and grow up to 12 mm in length when mature.

Life Cycle:

• House flies can quickly mature from eggs to adult flies.
• They breed on decaying organic matter like uncovered trash bins or pet food.
• Each clutch contains 120-150 eggs, which can hatch in 8-72 hours.
• Fly larvae take 3-60 days to mature, while pupae develop in 3-28 days.
• Once inside a house, house flies can land on walls, floors, or ceilings.
• Outdoors, they rest on trees, the ground, fences, compost piles, and trash bins. At night, they prefer resting near food sources 1.5-4.5 meters above the ground.

Buffalo flies are harmful pests for livestock. The constant bites from female buffalo flies can lead to weight loss in certain animals. Male buffalo flies primarily feed on pollen and nectar and are active during the day. Their bites can be very painful for humans. They have a needle-like mouthpart that they use to slice skin with a scissor-like motion.

Adult flies can grow up to 25 mm in length. They are dark brown to black, with either green or black eyes. The males have eyes that are close together, making them easy to distinguish from females, whose eyes are spaced further apart. The bite of a buffalo fly can be extremely painful.

Life Cycle:

• Mating begins in the air and finishes on the ground, where the female then lays a batch of eggs that may contain shiny or powder-like secretions to help retain moisture.
• The eggs are laid in clusters of 100 to 1000 on vertical surfaces above water or moist ground, providing a suitable environment for larvae development.
• The eggs hatch within 5-7 days.
• The flies overwinter in the larval stage and transform into pupae during the spring and early summer.
• The adult buffalo fly has a lifespan of 30 to 60 days.

The tsetse fly, scientifically known as Glossina, is a tropical fly species native to sub-Saharan Africa, classified under the Glossinidae family in the Hippoboscoidea superfamily. This fly is notorious for carrying and transmitting diseases, particularly sleeping sickness in humans and nagana in animals.

The tsetse fly carries the Trypanosoma parasite, which causes sleeping sickness in humans and nagana in livestock. Animals infected with nagana show symptoms such as fever, weakness, and weight loss, leading to eventual death if not treated.

In humans, after being bitten by a tsetse fly, the victim may develop a disease known as sleeping sickness, caused by the parasite Trypanosoma, which is transmitted through the bite. Early symptoms include fever, headache, muscle aches, and joint pain. After a few weeks, the disease progresses to confusion, disrupted sleep patterns, and eventually coma and death if left untreated.

This tiny creature is responsible for spreading death to 50,000–500,000 people and 3 million livestock every year. Unlike mosquitoes and other biting flies, both male and female tsetse flies feed on blood.

Some methods require no cost and only your time to implement. The steps we recommend involve making some changes both inside and outside your home to seal off potential fly hotspots and ensure effective fly control.

Effective fly control and prevention methods:

• Prevent fly entry – close windows and doors.
• Fly screens – install fly screens on windows, especially around kitchens and areas with waste.
• Cover food – flies spread diseases by landing on food before we eat it.
• Clean up – dispose of food scraps and spilled liquids after meals, and clean areas like under chairs and appliances in the kitchen.
• Trash bins/compost bins – ensure all trash containers are tightly covered.
• Doormats – make sure stains build up and are completely cleaned every month.
• Pets – clean up after them. Not only is pet waste a perfect breeding ground for flies, but they may land there before flying onto your food. Remove dead flies – they are food for other pests like carpet beetles.
• Water containers – cover with a fitting lid. Standing water – avoid allowing water to stagnate, as it creates a breeding ground for mosquitoes.
  Ponds – if you have a pond in your yard, consider adding goldfish, as they will eat mosquito larvae.
• Drains – ensure all drains are clear of debris to reduce mosquito breeding areas.
• House flies are usually attracted to decaying organic waste such as manure and rotting meat, while fruit flies seek sugary substances, mainly feeding on ripe fruits, spilled drinks, and fermented alcohol.

House fly (Musca domestica): The house fly is a major disease carrier and can infest all types of homes. They are attracted to all kinds of food, including human food, pet food, livestock feed, food waste, and even feces. Seeing adult flies is the most common sign of their presence and indicates a potential issue. You may also spot larvae as they crawl out of breeding materials to mature into pupae. Adult flies are 5-8 mm long, with gray thoraxes featuring four small stripes. Their abdomen is either brownish-yellow or tan. The thorax is covered in tiny hairs, which function as taste organs. Their compound eyes, with thousands of lenses, provide a wide field of view. The fourth wing vein is curved, and the wing tips are slightly pointed. The larvae are white and taper to a sharp point at the head, with two breathing pores at the rear and no legs. When mature, they measure about 12 mm.

Fruit flies (Drosophila species): Fruit flies typically invade fruit or hover around organic residues fermenting in bars, fruit orchards, potted plants, and beverage factories. They are 3 mm long, golden-brown or striped, with bright red eyes. Their abdomen drops lower while flying slowly, often in a looping motion.

Blue bottle fly (Calliphora vomitoria): Blue bottle flies are commonly found around garbage bins. As scavengers, they are attracted to pet feces and animal carcasses, and are known to spread diseases. The name 'blue bottle' comes from their shiny blue color, resembling that of a bottle. Adult flies range from 6 to 13 mm in length. Their larvae are similar to house fly larvae, except they can grow up to 19 mm when fully developed. They take 7 to 12 days to mature.

Gray fly (Sarcophagidae family): Gray flies range from 6 to 14 mm. Their thoraxes are pale gray with three dark vertical stripes, and their abdomens are light gray with dark spots arranged like a chessboard pattern. They are attracted to decaying organic waste, feces, and human food, posing a health risk.

Horse fly (Tabanidae family): Horse flies are pests of livestock. The relentless biting of female horse flies can cause weight loss in certain animals. Male horse flies mainly feed on pollen and nectar and are active during the day. Their bites can be quite painful for humans, and their mouthparts are similar to small knives, which they use to slice through skin in a scissor-like motion.

Flies are insects from the order Diptera (Greek 'di' meaning 'two' and 'pteron' meaning 'wings'). They possess a single pair of wings located on the middle thorax segment and a pair of balancing organs on the hind thorax segment. Some species, like those in the Hippoboscoidea family, lack wings entirely.

This large order contains over 240,000 species, including mosquitoes, houseflies, and others, although fewer than half of them have been thoroughly studied. It is a key order both ecologically and in terms of its importance to humans (medically and economically). The suborder of mosquitoes (Culicidae), in particular, is a major source of diseases like malaria, dengue, West Nile virus, yellow fever, and various other transmitted illnesses.

Flies, along with other two-winged insects, exhibit significant ecological diversity. Many fly species have entirely different lifestyles, such as:

• Endoparasitic species: Bot Fly.
• Ectoparasitic species: Black Fly, Sand Fly.
• Blood-feeding species: Horse Fly.
• Species that aid in pollination by feeding on pollen or nectar.

The body structure of an adult fly is divided into three main parts: the head, thorax, and abdomen, each containing distinct organs and functions.

Head:

• The fly's head consists of a pair of eyes, antennae, and the mouthparts. The antennae are responsible for scent detection, with the structure differing between males and females. The compound eyes are highly sophisticated, offering the insect a wide field of vision.
• Flies rely primarily on vision for survival, which is why their compound eyes are made up of thousands of sensitive lenses that continuously move. Some species can even perceive 3D images, while others have highly developed hearing organs.

Thorax:

• The thorax contains the fly's wings, balancing organs, and three pairs of legs.
• The fly's single pair of wings is located on the middle segment of the thorax, with a balancing organ, called the haltere, on the hind thorax. The legs, three pairs in total, are attached to the thorax and consist of five segments, with a strong skeletal framework.

Abdomen:

• The abdomen consists of 11 segments, though in some species, it is divided into 10 (with the last two segments fused). The last 2–3 segments house the reproductive organs, while the abdomen also contains the digestive organs.
• The fly's body is typically covered in fine hairs that function as sensory organs to detect food and scents.

The two-winged insect family is highly diverse in terms of ecology. Flies can be parasitic, including endoparasites like the bot fly and ectoparasites such as mosquitoes, black flies, sand flies, or lice. Many species of flies feed on the remains of dead animals.

Some species, like mosquitoes or horse flies, rely on blood to survive. Other flies play an essential role in plant pollination by feeding on pollen or nectar.

The fly lifecycle consists of: egg, larva (also known as maggot), pupa, and adult (with wings). The diet of larvae differs from that of the adult flies. For example, mosquito larvae live in water and feed on debris, while adult male mosquitoes consume nectar, and female mosquitoes feed on blood.

Flies depend heavily on their vision for survival. They possess compound eyes made up of thousands of highly sensitive lenses that detect movement. Some species, such as the fly Ormia ochracea, can perceive 3D images and have evolved hearing organs.

Flies feed on a variety of substances, including human and animal waste, particularly those containing infectious pathogens such as saliva, mucus, vomit, feces, blood, and decaying tissue. The structure of their mouthparts is adapted for lapping and sucking liquids. As flies feed, they regurgitate and defecate, and these substances may carry pathogens. Additionally, flies transport pathogens on their bodies, serving as vectors for disease transmission.