Where Do Horse Flies Come From?

Horse flies are not just annoying, they can be deadly for horses as well. The horse flies, which appear harmless, are considered more harmful than any other type of flies because they release anticoagulants that keep the blood flowing for a noticeable amount of time.

Whoever gets bitten by horseflies, whether it’s a horse or human, would suffer from burning sensation, swelling, and itchiness. So, it’s fair to look for ways to get rid of them and to think where exactly they come from? 

In this brief post, we would like to update our loyal readers on where the horse flies come from. Where do they build their home, reproduce, get double in number, and live a balanced life? So, let’s have a look;

Where Do Horseflies Come From? 

The horse flies, which are known for biting causing a sharp burning sensation, itching, inflammation, and swelling, develop and come from the following horseflies friendly sites;

  • Saltwater marshes
  • Streams
  • Moist forest soils
  • Even moist decomposing wood
  • Freshwater

These are the few sites that are believed to be favorable for the horse flies’ development and growth, most of the total horseflies population develop and come from the same sites. 

Salt marshes

Salt marshes can be defined as coastal wetlands that are swamped and drained by salt water brought in by the tides. Such horsefly-friendly sites usually appear in temperate and high-latitude low energy shorelines. The salt marshes can be emerging, stable, or submerging and generally the horse flies find a home in all of the above-mentioned kinds of salt marshes. 


Stream, a body of water in which water flows within the bed or banks of the channel, is another place where horse flies develop and grow in abundance.

Streams are just a reward from nature, besides being home to horse flies, they also act as a corridor for fish and wildlife migration as well. There are several types of streams, the eight recognized ones are Alluvial Fans, Braided Streams, Deltas, Ephemeral Streams, intermittent Streams, Meandering Streams, perennial Streams, and Straight Channels Streams. 


Moist forest soils

Moist forest soils are also responsible for giving favorable conditions for the horseflies’ growth. Such soils that are favorable for the horse flies’ growth are commonly found in South America, West Africa, Southeast Asia, Thailand, Burma, Sri Lanka, Vietnam, and the Caribbean.

Moist soils, like all other favorable conditions for horsefly growth, provide ideal circumstances for the said insects to grow and live a balanced life. 

Even moist decomposing wood

As you might have judged, moisture does not just attract horseflies it also gives an ideal condition for the said insect’s growth.

Even moist decomposing wood appears harmless but in reality, it is the same case. Let alone even moist decomposing wood, every excessive wet organic matter around the barn and pasture would keep providing a favorable environment for the horseflies’ growth. 


The slow-moving fresh water can also be taken as horse flies’ second home. Some species of horse flies are also found in fast-flowing water as well but the slow-moving blesses horse flies with all favorable conditions for life.

Other than the favorable living condition, horse flies are found near freshwater for other reasons as well. The major reason is the shiny surface of freshwater. 


Other Places Where Horseflies Can Possibly Come From

No doubt, the majority of the world’s horse flies population is residing and reproducing in salt marshes, streams, moist forest soils, even moist decomposing wood, and freshwater but there are some other places as well where such insects do not mind building their homes. The other places that can be taken as horseflies homes are;

  • Swamps
  • Bogs
  • Shallow lakes


In simpler words, swamps are transition areas that are neither total water nor total land. There are two types of swamps; freshwater swamps and saltwater swamps.

The freshwater swamps usually exist inland whereas the salt ones are located along with the coastal areas. 


Bog, that is also referred to as bogland, is one of the four main types of wetlands.

Other than the typical names(bog and bogland), the said ideal condition is also referred to as mosses, quagmire, mire, and muskeg. Bogs appear where the surface is acidic and low in nutrients and they are usually covered with heath or heather shrubs. 

Shallow lake

The shallow lake is just a regular lake but the depth distinguishes it from the regular lakes. It can be permanent or semi-permanent and usually have depth up to 15 feet.


Hi, I am Waqar and active in the horse world since 2012. I have MSc (Hons) in Agriculture from the University of Agriculture Faisalabad. I love to solve equine health care issues and note down in the form of research papers. I have written hundreds of equine health care, accessories, names, and history-related blogs. My equine related work is watering a lot of horse-related magazines and blogs.

Leave a Comment