What Do Blow Flies Look Like?

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What are blow flies really? Are they your standard house flies? What do blow flies look like? Well, I’ve researched immensely about blow flies just so that I could write this article and make it easier for you to know about these pests! So, keep reading!

What are blow flies?

blow flies

Insects that are commonly called “blow flies” are in the family Calliphoridae. They are metallic blue or green and have a loud, distinct buzz. They do not bite humans and can be beneficial because they eat carrion. But you don’t really want them around your home!

Now, they are a close relative to the common housefly and share many of the same habits, including feeding and breeding. Therefore, it is not uncommon to mistake a blow fly to be a house fly. But, after reading this article, you’ll know better than to make that mistake.

The fact is that blow flies can be identified by their metallic coloring and typically have a lifespan of around two weeks.

In addition to their unsightly appearance, blow flies are known for spreading filth and bacteria around with them wherever they go. This can include food, garbage, and even feces.

Consequently, it is important to get rid of any blow flies you may see in your home as soon as possible.

What do blow flies look like?

Blow flies are a type of fly that is found all over the world. They are easily recognizable by their characteristic markings and habits.

Blow flies have sponge-like mouth parts which they use to soak up liquids, and they also have feathery hairs on their terminal antennal segments, which help them sense their environment.

In addition to their spongy mouths and hair, blow flies are also characterized by their metallic sheen, which typically comes in the colors green or blue. And yes, I know what you’re thinking. That is too good a color for a dirty fly.

The maggots of blow flies, of course, don’t look like adult blow flies. Maggots are the larval stage of blow flies, and they’re characteristically soft-bodied. They measure 9 to 22 mm in length, and they have a dark head and a light-colored rear end.

What causes blow flies to enter and settle into your home like unwanted roommates?

blow fly infestation and maggots

Blow flies are attracted to things nearby that provide food. This can be anything from rotting meat to a piece of fruit that has been left out too long. Blow flies are also attracted to organic materials that have decayed or spoiled.

This means they are often found near garbage cans, in compost piles, and around dead animals. If you have a blow fly problem in your home, it is likely because you have something nearby that is attracting them.

If blow flies are appearing inside your home, it means that something is attracting them there. It could be a dead animal or some other organic matter. If you see a lot of blow flies, it might be time to call an exterminator to get rid of the source of attraction.

In the fall and spring seasons, blow flies can come into your home. They are looking for a place to hibernate or lay eggs, so they will try to find their way into your house.

Most of the time, they will not cause any harm, but it is important to be aware of them so that you can take steps to prevent them from entering your home.

In addition, there are some things you can do to discourage blow flies from entering and settling into your home, like unwanted roommates. One is clearing away any problem areas near where the blow flies are being drawn.

Another is keeping a close eye on your pet’s health, as an open wound may attract wandering female blow flies that will lay eggs on them.

Are blow flies dangerous for you?

Yes, blow flies can be dangerous for you. They are known for their characteristic blue or green color, as well as their long, protruding proboscis.

Blow flies can be dangerous to both animals and humans, as they are carriers of bacteria and germs. They may also lay eggs in an animal’s eyes, ears, or nose, which can cause serious health problems.

What is the life cycle of a blow fly?

Blow flies go through a complete metamorphosis, meaning they undergo a transformation from one life stage to another. This process takes place over the course of several weeks and involves three larval stages: the egg, the maggot, and the pupa.

The life cycle of the blow fly starts when the female blow fly lays eggs in an animal carcass, wound, eyes, ears, or nose. The first-stage larvae hatch within 24 to 48 hours and start feeding on the rotting flesh.

The larvae go through three more molts before they form a pupa and emerge as an adult fly. This entire cycle can take roughly three weeks!

What are the signs of a blow fly infestation that you need to watch out for?

multiple blow flies is a sign of an infestation

Blow flies are most common in the summertime when the weather is warm and humid. They can be found indoors and outdoors, but they prefer to live in warm, moist environments.

Blow flies are attracted to food and decaying matter, so if you see a fly that is larger than other houseflies and has a metallic blue or green sheen, it is likely to be a blow fly.

If you’re wondering what the signs of a blow fly infestation are, look for a high concentration of flies and a buzzing sound.

Blow flies thrive in warm and moist environments, so if you notice an increase in these conditions around your home, it’s likely that you have a blow fly infestation.

While it is harder to spot blow fly larvae, there are signs that you need to watch out for. If you see a mass of maggots in your food or notice fly eggs, these are both indications of a blow fly infestation.

However, when the larvae do emerge, they will be easier to deal with as they will be near the surface.

What is the total life span of a blow fly?

The development of a blow fly takes around two to three weeks to complete. The eggs hatch, and the larvae feed on decaying matter.

Once they have matured, they will pupate and then emerge as flies. Blow flies can live anywhere from two weeks to a month, depending on the species.

What do you need to do to get rid of blow flies using natural methods?

Sanitation is the first line of defense against blow flies. This means keeping your house clean and free of any organic material that can attract the flies. You can also use natural methods to get rid of blow flies, including using essential oils, fly traps, and exclusion methods.

Here are some basic things you can do to get rid of blow flies naturally –

  1. by keeping your trash sealed and taking it out on a regular basis. If you have a lot of garbage, consider getting a composter to reduce the amount of food waste that will attract blow flies. You can also use traps to catch the flies or try natural methods like using essential oils or vinegar.
  2. You need to remove animal waste from your yard on a regular basis. This will help to cut down on the number of fly eggs that are laid in the area.
  3. By repairing screens on doors and windows. Blow flies are able to enter your home through small cracks, so it is important to fix these entry points. Additionally, you can use natural methods like fly traps or essential oils to get rid of blow flies.

Blow fly vs. house fly – how can you tell the difference?

blow fly vs. house fly

There are essentially three main ways in which you can differentiate between blow flies and house flies

  1. The easiest way is by their coloring. House flies are much darker than blow flies and have smaller hairs on their bodies. 
  2. Another distinguishing feature is the way they walk. Blow flies walk in a jerky motion, while house flies walk in a more smooth manner.
  3. Blow flies usually go for things that you wouldn’t eat, such as dead animals or feces, while house flies are attracted to all types of food.


Blow flies are flies with a metallic sheen. There certainly are some more physical characteristics of blow flies. But, this is the way I identify them, and I must say, you can’t really go wrong when you stick to the simple!

About the author

A biotechnologist by profession and a passionate pest researcher. I have been one of those people who used to run away from cockroaches and rats due to their pesky features, but then we all get that turn in life when we have to face something.