Fly report (viewer discretion advised)

Flies: Dyptera

Fascinatingly, Diptera is broken into 2 suborders, the two are Nematocera and Brachycera, because of their different antennae. The superb Nematocera is known by their long bodies and somewhat feathery antennae, unlike the Brachycera, who have rounder bodies and a short antennae.

Would you believe if I told you, that flies are part of many cultures’ expression of very evil things? A spirit being, that in Navajo culture is named Big Fly… and Beelzebub, which is in Christian demonology, a demon fly.


People even make art with flies – a provocative art piece called A Thousand Years, by Damian Hirst, had a cow’s head which showed the decomposition of a cow, in a glass jar, along with 1000 flies, which featured the appetite of the pests, and showed the life-cycle of a fly.

A couple bugs, for example dragonfly, have the word “fly” inside their name, but this does not mean they are flies (dipterans). The word fly is used occasionally to name a small flying bug. The phrase “true fly” means a real fly from the Dipteran family.

There are 120,000 species of fly that are known. The actual number of species of fly is probably much bigger. I can’t name all of them so I will tell you a couple of them. There are: horsefly, bluebottle fly, cluster, sand, fruit, house, drain, and flesh fly.

Yay, the toad just ate a fly, but would you still be cheering if I said that some flies actually eat the toad? The lucilia bufonivora, which is called “buffy”, lays its eggs in the brain of a toad, which, after it hatches, makes the toad look more like a turtle.

But Buffy isn’t the only increasingly disturbing fly in the world – allow me to introduce to you the great acroceridae, also known as the “small-headed fly.” It may seem nice and harmless when you are seeing it delicately drinking flower nectar, but things are not always what they seem. An example of a cute nice creature (also with a small head) is the slow loris.

This animal has the cutest eyes you will ever see in you life, but watch out, it can squirt venom from its elbows. The fly is the same: the acroceridae is cute, but evil.

The cute small headed fly have either cool or disgusting larvae, depending on the way you see it. The maggots run, hop, and start looking for a spider from the moment they pop out of their little eggs. If they find a good big one they crawl in its body, and immediately start devouring the spider alive. It spends a whole decade eating the poor spider alive, but you will be shocked to learn that this cannibalism extends the spider’s life, up to 12 years of age!  Panopinae is a subfamily of flies that live in Asia, Australia, New Guinea and Indonesia, and our spider-eating fly is a part of it. 

The tiny head is fluffy and greyish black. Acroceridae also has a black furry body that’s shiny. It has white legs emerging from its body and two wings coming out from the sides of its body.

During the day when baby birds are awake a fly called Philornis downsi’s larva hide in the nest where it can’t be seen, then at night the maggots strike! They come out of hiding to eat the flesh and blood of the chicks.
These evil maggots have such a big appetite that they almost have the achievement of making Darwin’s finches of the Galápagos Islands extinct! The flies have been on this island since the 1990s: that’s 29 crazy years of eating poor defenseless chicks!

Have you ever said that you pity a bat? No? Well this fly will make you pity them.

The families of fly I am talking about are the Nycteribiidae and Streblidae. These families suck the blood of bats, but mostly vampire bats. They spend their whole life attached to a bat, sucking away at its blood. Imagine: you have a mosquito on you, and it’s sucking your blood. You try and struggle and flail crazily but it won’t come off. That is sort of how a bat with a fly stuck on it feels.

Here is the most disgusting, disturbing, and upsetting fly in the world, the sheep nose bot fly. The reason that it is called that is because it usually lays its eggs in a nose of a sheep. But flies aren’t that smart and have no sense of direction, so… if this little fly flies around and goes into your eye, you are toast. If that will happen to you, you have a little maggot in your eye that is writhing around in your osculatory orbit and silently drinking your eye fluid. This maggot is called the Congo floor maggot, and I am glad to say you will only have a chance of getting this maggot in your eye if you are sleeping on a dirt floor. These evil creatures can be stopped by something called a bedpost. And if you enjoy sleeping on the floor and have one of these evil creatures in your eye you can just count the days for ten weeks for the maggot in your eye to turn into an adult and change its eating habits from human blood to human carcass.

These spectacular insects are very important to humans – they pollinate our flowers, second only to bees and how do we thank them… we swat and try to kill them. They also recycle when they feed on waste such as scat and dead animals. They are incredibly important to the food chain.

“Where are flies found?”, you may ask, well the simple answer is… (drum roll please) EVERYWHERE, except for Antarctica. Some of them are very well known such as the housefly, mosquitos, gnats, black flies, midges, and last but not least, the fruit fly. Also fossils are found from around 240 million years ago and flies came from the Permian Age are guessed as living about 260 million years ago. 


Swarming is when many flies come together to attract females, and when they swarm there are so many flies that it looks like a cloud.

“Growing up as a fly wouldn’t be hard,” you might think, you also might think “it might be gross but not hard considering their three day life-span,” Well… you’re wrong. Flies have many animals trying to gobble them up, the eggs, for instance, are eaten by insects and other creatures. Do you want to hear about some animals that kill flies… well of course you do! Flies are also consumed by birds, bats, frogs, lizards, dragonflies and spiders.

Flies have something called a mechanoreceptor that allows them to feel and touch, and chemoreceptors that lets them smell and taste.

Flies can fly very well thanks to halteres; halteres let the fly fly; they let it rapidly flap their wings and give the flies balance and guidance; without these halteres, flies are unable to fly. 

Halterseses vibrate when the fly is soaring through the sky, and look slender and threadlike. Hey, put some weights of equal weight in both of your hands and use them to build momentum and energy with your jump; that is sort of what halteres do. I have tried it and it gave me a sense of liftoff. The term comes from the 1550s when people studying the fly couldn’t understand how easily they zoomed around. When they looked closely, they used this sportsman’s term to better identify the phenomenon. (Halteres: from Greek haltēres (plural), from hallesthai ‘to leap’.)

The fly family has two compound eyes on both sides of their heads and some species have three ocelli (the simple eye, or the single lens) on the top of it. The interesting compound eyes can be close or far apart from each other. Human beings obviously have two eyes, and these are classed as simple – as opposed to the compound eye, where a given insect can have thousands of lenses stacked tightly together, to create that other-worldly effect. I mean, have you ever looked at an extreme close-up of a fly’s compound eye?

Flies lay eggs in different sizes and shapes depending on the species. The pesky house fly lays eggs that look like grains of white rice. In 24 or less hours of being laid, larvae hatch out of the eggs. These larvae look like small, white worms. These disgusting, squirming things, are called maggots. How would you like to be called a maggot (even if you were tiny and disgusting?)

Did you know that the life cycle includes the egg and maggot period, then the larva period, then to pupa, and finally to adult? I didn’t. But that’s not all: the eggs that I know of, don’t eat! But flies’ eggs eat, because they are maggots! These white squirming, and hungry blobs are laid on a larva food source so when the egg turns into the larva it is in a safe place to grow and turn into a pupa.

Many flies’ larval stage is lengthy, but they are developed in protected areas, such as carrion, fruits, fungi, vegetables and inside its host. 

The larval stage of these hundreds and thousands of subspecies varies, but we can safely say that the hatching of the fly from the maggot can be a nightmare for people… imagine, for a second, if you accidentally left some food out before going on a three-day trip. Upon returning, your nose is greeted by a most unholy stench, and a fly buzzes right under your ear. 

Pupae have multiple looks, the pupa is between larva and adult in the life cycle of a fly. Pupa are “obtect”, which means to have future limbs visible, wrapped around the thorax. 

The adult stage of a fly is short, as its purpose is to mate and reproduce.
So just remember when you see a fly, before you kill it just think about this report and remember all the reasons flies are good and all the ways flies can be utterly disgusting and evil, and decide if you are gonna kill it or not. But probably by the time you remember all of this the fly would have flown away.

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