What do Flies Eat? Do they really throw up on your food?

Last Updated on: January 28th, 2020 at 8:09 pm

Few years back, Orkin conducted a survey and asked participants – “Would they be more likely to eat their food if a fly landed on it, or if a cockroach crawled over it?”

And the survey results were – nearly 70% of people said that they would still eat the food by digging out the fly.

Whereas, only 3% people would eat their meal if a cockroach crawled over it.

Although, the survey results are not so surprising. But what concerns me the most – is that people actually do not find flies as dirty as cockroaches.

If you are one out of those 70 percent, then this article is going to be an eye opener for you. In this article, we will see – what do flies eat and how do flies eat.

What Do Flies Eat?

what do flies eat

There are thousands of different species of flies. All these different species of flies eat different kinds of food. The feeding habits of one species is totally different from another. For example: house flies feed on rotting organic matter where as horse flies (female horse flies) need a blood meal.

In the following section, I will enlist what different species of flies eat.

Recommended Reading: How to get rid of flies

House Flies:

Adult house flies mostly feed on decaying matter, sugar or flower nectar. Sometimes they also feed on honeydew left by aphids. House flies do not have mouthparts that allow it to chew.

Larvae of house fly feed on organic matter found near the breeding site. They have a curved hook like structure with their mouth and they use it to scrape off small solid pieces of food and consume them.

Fruit Flies:

Fruit flies normally feed on the yeast cells that grow on rotting fruits and other sugary substances. Apart from this adult fruit flies also consume fermenting liquids and alcoholic beverages. They are particularly fond of bananas among fruits.

Adult fruit flies puncture the skin of overripe fruits and lay eggs there. Fruit fly larvae also feed on the decomposing fruit.

Blow Flies/Bottle Flies:

Bottle flies mostly like to eat fresh or decaying meat. Blow flies are usually the first insects to attack a dead animal carcass. They are also known for burrowing themselves into the animal carcass and lay eggs there. In addition to these, adult blow flies also consume garbage, or feces.

In larval stages, blow flies feed on the rotten meat or other rotting matter present near the breeding site.

Horse Flies:

Horse fly is one of few species of flies that have cutting and tearing type mouth parts. The bite of a horse fly is very painful. Horse flies have scissor-like jaws that can tear flesh.

Generally, male horse flies feed on flower nectar, honeydew, plant juices and other plant liquids. But female horse flies need a blood meal in order to get enough protein to lay eggs.

In order to get the blood meal horse flies bite cattle or humans and draw blood. Horse fly larvae feed on small insects present near the breeding area.

Recommended Reading: How to get rid of horse flies

Cluster Flies:

Cluster flies generally feed on flower nectar and other plant juices. In absence of it, they feed on the decomposing organic matter.

Cluster flies lay eggs in soil cracks, particularly moist soil cracks. In larval stages, cluster flies exhibit a parasitic behaviour. Cluster fly larvae enter the body cavities of earthworms and feed on them.

Drain Flies:

Drain flies eat decomposing organic matter and sewage. Drain flies also do not have mouth parts to chew and hence they feed on semisolid gelatinous matter and slime present in the drains.

Drain fly larvae feed on sediments, decaying vegetation, microscopic plants and animals present in the drains.

Recommended Reading: How to get rid of drain flies

Crane Flies:

Adult crane flies generally have a very short lifespan of just few days. So, they are mostly active in mating and laying eggs after reaching the adulthood and are very seldom seen eating.

However, sometimes they eat pollen and nectar from flowers.

But in larval stages crane flies eat a lot. Crane fly larvae can eat anything from grass roots to small insects.

Some crane fly species are herbivores and during larval stages they feed on seedlings, flowers, plant roots, fungi and decomposing wood.

Other carnivorous species of crane flies, in larval stages, eat small insects, mosquito larvae etc.

How Do Flies Eat?

Most species of flies do not have mouth parts to allow them to chew food. Instead of teeth, flies have a special mouth part called a proboscis.

Proboscis an elongated sucking mouthpart that is typically tubular and flexible.

how do flies eat

A fly uses its proboscis to drink liquids.

So, in order to eat solid food, they vomit their digestive enzymes over the food. Digestive juices start breaking the solid food into small pieces and then using proboscis they slurp it up.

Sorry, I know that was gross!

About Ankit Zadi

My name is Ankit Zadi, and I can call myself a 'Fly Expert'. My adventures with flies began when we shifted to our new house seven years back. My goal on this website is to share everything that I know about flies. Check out my full story here.