Blow flies are fascinating and problematic insects. Known for their metallic, shiny appearance, these flies play an important role in decomposing organic matter but can also become a nuisance when they gather in large numbers. Here, we’ll cover blow fly identification, behaviors, and life cycle and provide tips on how to get rid of and prevent infestations.

Blow Flies in Florida

Blow flies are one of the many types of flies commonly found in Florida, especially during the warmer months. They are particularly attracted to decaying organic matter, making them prevalent in areas with abundant carrion, animal feces, and food waste. In Florida’s humid climate, blow fly infestations can become more frequent, especially near homes and businesses that provide access to food sources.

What Do Blow Flies Look Like?

Blow flies are known for their shiny, metallic bodies. Their colors are often bright shades of blue, green, or copper. They are larger than common house flies, usually measuring between 6mm and 14mm in length. Blow flies’ wings are transparent and rest flat over their backs when they’re not flying. 

One of the most noticeable features of blow flies is their large eyes. These large, striking compound eyes are composed of thousands of lenses, giving them a broad field of vision and a metallic sheen. They also have short antennae that they use to detect scents. These features are key to how they navigate and find food.

Signs of a Blow Fly Infestation

Blow flies are attracted to decaying organic matter, so one of the primary signs of an infestation is the presence of dead animals around your property. Blow flies can also be found near food waste, including rotting fruit or improperly disposed of food scraps. You’ll typically see large numbers of blow flies swarming around these areas, and sometimes you may notice the telltale maggot-like larvae characteristic of their life cycle. 

Blow flies thrive best in weather that is warm and humid. They normally lay their eggs on meat, fish, or dead animals but will also lay eggs in decomposing organic matter, like garbage, animal manure, decaying vegetables, grass clippings, and poorly managed compost piles. If you notice an unusual number of flies indoors, it could indicate a blow fly infestation. 

Under ideal temperatures, blow flies can develop from egg to adult in as little as 7 days. Many homeowners have witnessed this behavior, such as the mass emergence of maggots crawling from their backyard trash cans when kitchen waste placed in these trash cans was not sealed in a plastic trash bag.

Habitat, Diet, Life Cycle & Behaviors

Understanding blow flies’ habitat, diet, and life cycle is crucial in controlling their presence around your home or business.

Where Do Blow Flies Live?

Blow flies are found worldwide but are especially common in warm climates like Florida. They thrive in areas with abundant decaying organic matter, such as around animal carcasses, garbage, and compost piles. 

Their natural habitat is often in areas rich in rotting material, such as forests or fields. In residential and commercial settings, blow flies are frequently attracted to areas near trash bins, food waste, or dead animals, including animal carcasses in the home or yard.

Diet

Blow flies are scavengers and primarily feed on decaying organic matter. They are often the first to arrive at a carcass or other rotting material. Adult blow flies typically feed on liquids, such as those found in decomposing animal carcasses or rotting food. The larvae, or maggots, feed on the decaying tissue of dead animals during their larval stage. They play an essential role in breaking down organic matter in the environment.

Life Cycle

The life cycle of a blow fly begins when the adult fly lays eggs on decaying organic matter, typically a dead animal or food source. These eggs hatch into larvae, or maggots, which then feed on the decaying material. 

As they grow, they go through several instars (developmental stages) before pupating. Once they pupate, they form a hardened case known as a pupa. Inside the pupa, the blow fly undergoes a transformation into an adult. 

The adult blow fly emerges from the pupa and begins the cycle again. Depending on environmental conditions, blow flies can complete their life cycle in a matter of weeks.

Behaviors

Blow flies are attracted to the scent of decaying organic matter, which they detect using their antennal sensors. They are strongly attracted to human foods and garbage, making cooking outdoors difficult when they are present. 

They are known for their ability to locate carrion from great distances, picking up faint traces of odor of decay, and can fly up to 12 miles in search of a suitable carcass to lay their eggs. These flies are also important pollinators, although they are more commonly known for their scavenging habits. In large numbers, blow flies can cause significant problems, especially when they invade homes or businesses searching for food sources. 

Are Blow Flies Dangerous?

The primary threat from blow flies is the distribution of disease-carrying organisms that affect humans, such as salmonella, food poisoning, dysentery, cholera, various parasitic worms, and many others. Their larvae can contaminate food, leading to health risks and foodborne illnesses.

As with house flies, they may be involved in the transmission of disease agents acquired from garbage or animal feces and subsequently deposited onto human foods. Although cases are rare in the US, blow flies are also responsible for myiasis, a condition in which fly larvae infest living tissue, which can cause severe infections in some cases. Blow flies are especially dangerous when they infest animal carcasses and then human food.

How to Get Rid of Blow Flies?

Addressing the root cause is the first step in eliminating a blow fly infestation. They are attracted to decaying organic matter, so locating and removing potential food sources is crucial as a first step: inspect your property for dead animals, food waste, or rotting organic material, and promptly dispose of these items to eliminate their breeding grounds. Once the source is removed, clean and sanitize the affected areas thoroughly, especially around garbage bins, compost piles, and outdoor waste containers. Using disinfectants can help kill bacteria and neutralize odors that attract these pests.

In some cases, insecticides may be necessary to eliminate adult blow flies and prevent their larvae from developing. Be sure to follow the manufacturer’s instructions for safe and effective application. Installing insect light traps is perhaps the best ongoing solution, especially in commercial environments.  

If the infestation is severe or persists despite your efforts, it may be time to call a professional pest control service like Florida Pest Control. Our experts have the tools and experience to eliminate blow flies efficiently. If you are dealing with a blow fly problem, contact your local fly control specialists for assistance.

Blow Fly Prevention Tips

Preventing blow fly infestations starts with proper waste management. Always store food scraps, garbage, and compost in sealed containers, and dispose of waste regularly to reduce attractants. Inspect and seal entry points like doors, windows, and vents to prevent flies from entering your home. Regular cleaning is also essential, especially in areas where food waste is common, such as kitchens, outdoor dining spaces, and trash storage areas.

Additionally, it’s important to remove decomposing matter from your property promptly. This includes disposing of fallen fruit, removing dead animals, and clearing away rotting vegetation. By taking these proactive steps, you can significantly reduce the risk of blow fly infestations and maintain a clean, pest-free environment.

Do You Have a Fly Infestation Problem? We Can Help.

Dealing with a blow fly infestation can be overwhelming, especially when the problem becomes severe. If you’re struggling to manage blow flies on your property, contact Florida Pest Control for professional assistance. Our experienced team can identify the source of the infestation and provide tailored solutions to eliminate these pests effectively.

We also offer advanced tools like Lumnia insect light traps, designed to attract and capture flies discreetly and efficiently in commercial kitchens and food outlets. 

Click on the button below to get a free quote for residential fly control or explore other fly species on our house fly facts & identification page.

FAQs

Do blow flies bite?

Blow flies do not bite. These flies do not have the mouthparts necessary for biting or stinging. Instead, they feed on decaying organic matter, such as dead animals, rotting food, or animal feces. While they may be attracted to human foods, they are not a threat in terms of biting or stinging.

How long do blow flies live?

The lifespan of a blow fly varies depending on environmental conditions. On average, an adult blow fly lives for about 2 to 4 weeks. Under optimal conditions, such as warm and humid environments, blow flies can develop from egg to adult in as little as 7 days. This rapid development cycle allows blow flies to reproduce quickly, especially during warm weather.

Do blow flies lay eggs in humans?

Blow flies do not lay eggs in humans. They tend to lay their eggs on decaying organic matter, such as dead animals or rotting food. While they do not target living humans for egg-laying, their larvae can occasionally infest wounds or sores in a condition called myiasis, where the larvae feed on human tissue. This is more common in tropical regions or areas lacking hygiene.

Are blow flies scavengers?

Yes, blow flies are scavengers. They feed on decaying organic matter, including dead animals, garbage, and animal manure. Their larvae, or maggots, feed on the decaying tissue, playing an essential role in breaking down organic matter. Blow flies are often among the first insects to arrive at a carcass, and they help decompose and recycle nutrients back into the environment.