Flies are annoying whether they’re buzzing around your head, biting you, or living in your drain.
Many flies can’t harm you but they can certainly drive you crazy. Getting rid of them is a necessity when you find them multiplying in your house.
How long do flies live? The lifespans of different fly species vary greatly. House flies and cluster flies usually live for a month, from egg to death as an adult. Gnats, mosquitoes, black flies, and blow flies only live for a couple of weeks. Crane flies, deer flies, and horse flies can live for as long as 3-5 years.
Knowing how long a fly lives can help you determine the best way to get rid of them if you’re finding them buzzing around your house.
Let’s take a look at the life cycles of flies and how to get rid of them.
The Stages of a Fly
It’s estimated that there are 120,000 species of flies, but of course, it’s almost impossible to count them all.
Even though there are many different species of flies, they all go through the same stages of life: egg, larva, pupa, and adult.
The life cycle of a house fly will be used as an example, but note that each species has variations in terms of what their larva and pupa look like.
Egg
Fly eggs are usually white and look like grains of rice. They’re so small that you sometimes might not notice them at first.
House flies usually lay their eggs one by one in groups, but this varies from species to species.
Most fly species require wet conditions for the eggs to hatch. You’ll frequently find eggs laid in wet garbage, puddles of water, mud, or manure.
If you don’t want flies, keep everything dry.
Larva
Larvae are typically white or yellow. You’ll see them wiggle around in the bottom of garbage cans or in manure or mud.
They eat whatever they were born in until they reach their pupa stage. This is an important stage for many flies.
Improper temperature and nutrients can result in a small fly.
If you’ve ever seen a small house fly, that doesn’t mean it’s a “baby fly” that isn’t finished growing; it means that it didn’t grow in the right conditions while it was in the larva stage.
Pupa
The pupa is the hard case that forms around the fly while it grows from a larva to an adult fly.
The pupa is very much like a caterpillar’s cocoon, but it’s usually buried in the ground, manure, or sometimes underwater.
For house flies, the pupa turns from white to black. Once it’s black, the fly emerges.
All flies have to break out of their pupa casing.
Some species, like the house fly, use their head to break out of it, while other species use their mouth to chew their way out.
This period can take a long time for many flies. House flies can take as little as two days in warm weather or almost a month in cool weather.
Horse flies, on the other hand, take four weeks to finish pupating.
Adults
This is the stage you’re likely most familiar with. After flies emerge from the pupa, they’re full-grown adults who are ready to mate and repeat the life cycle.
Some flies can’t mate until a day or so after leaving their pupa.
The lifespan of adult flies varies. Those pesky house flies can live for up to a month, while phorid flies are only adults for a few days.
Some flies, like face flies, hibernate in the winter and thus will live for several months as an adult.
Unless they’re hibernating, flies are mating and laying eggs as an adult.
Some flies lay eggs in batches and will lay them several times throughout their adult life. Others can only lay eggs once.
When it comes to pest control, it’s important to make sure your home and yard are free of ideal breeding grounds for flies so that the adults won’t have a decent place to create the next generation.
Lifespans of Common Flies
With 120,000 different species of flies, it’s difficult to track them all and know their lifespans; however, we can take a look at the most common flies that plague our homes and yards.
House Fly
The house fly needs warm weather to develop correctly. Warm weather speeds up larva and pupa stages, and cold weather will slow them down.
Lack of nutrients will also cause the flies to be smaller than usual.
You might see smaller flies in the winter than in the summer because it’s difficult for flies to find warm conditions to lay eggs.
You’ll find eggs, larva, and pupa in garbage cans and manure.
Life Stage |
Duration |
| Egg | < 24 hours |
| Larva | 2 weeks – 2 months |
| Pupa | 2 – 20 days |
| Adult | 2 weeks – 1 month |
Gnat
Gnats usually lay eggs around water during the summer. In coastal areas, gnats can lay eggs all year long because of the warmth and water availability.
They mate while they’re swarming, so it’s important to try to get rid of swarms when you see them in the evenings.
Gnats usually lay around 300 eggs but it’s possible for them to lay 1,000.
Fruit flies are commonly mistaken for gnats and can be terribly annoying to deal with. You can learn more about fruit fly identification and elimination here.
Life Stage |
Duration |
| Egg | Several days |
| Larva | About a month |
| Pupa | About a week |
| Adult | 1.5 weeks |
Mosquito
Depending on the species of mosquito, they will lay their eggs in the mud next to a body of water, in crevices in a tree stump, or even in a bucket of water.
The eggs hatch as soon as they have enough water. If the eggs are laid in a bucket of water, they’ll hatch very soon.
If they’re laid in mud or in a tree, they’ll likely hatch when it rains and the crevice they’re in is filled with water.
Larva typically live in water and will come up for air quite frequently. Even in the pupa stage, they’re capable of swimming through water.
Warm weather is ideal and allows for rapid progression through the life stages.
Life Stage |
Duration |
| Egg | As soon as they have enough water |
| Larva | 7 – 10 days |
| Pupa | A few days |
| Adult | Males: 5 – 7 days
Females: 1 – 2 weeks in nature |
Other Common Flies
The following will show you the lifespans and adult lifespans of common flies. There’s quite a bit of variation between species.
It should be noted that face flies hibernate through the winter, so it’s difficult to know exactly how long they live.
It only takes about three weeks to go from egg to adult, but their hibernation pattern in the winter allows them to live for quite a long time (compared to other flies).
Type of Fly |
Total Lifespan |
Adult Lifespan |
| Black fly | 2 – 3 weeks | About 1 week |
| Blow fly | 2.5 – 3 weeks | 5 days |
| Cluster fly | 30 – 50 days | About 15 days |
| Crane fly (mosquito hawk) | 1 – 5 years | 10 – 15 days |
| Deer fly (yellow fly) | 1 – 3 years | 1 – 2 months |
| Drain fly | About 40 days | About 20 days |
| Face fly | Several months | Several months |
| Flesh fly | About 21 days | About 1 week |
| Horse fly | 1 – 3 years | 1 year |
| Phorid fly | 20 – 40 days | A few days |
How to Get Rid of Flies
It’s important to get rid of flies as soon as you see them because they can easily multiply and become an infestation.
You can use two methods: prevention and elimination.
Prevention
Prevention is best done with DIY methods. You can try the following methods:
- Turn on a fan.
- Citronella candles.
- Herbs like basil or mint (more deterring plants listed here).
- Remove standing water.
- Keep garbage covered.
- Clean up after pets.
Locating and sealing possible entry points is critical for prevention as well.
Our guide to repelling flies provides additional information and tips. Don’t miss it!
Elimination
Elimination involves killing them when you see them. Natural methods are always better than pesticides.
Pesticides are harmful when ingested because they contain harsh chemicals. Instead of pesticides, try the following:
- DIY fly trap with sugar and water in a jar.
- Light traps that trap or zap flies.
- Sticky traps.
If infestation is already an issue, read ” How to Get Rid of Flies” and check out our top trap recommendations for help.
Conclusion
Flies can live for just a few weeks or as long as five years. This depends on the species and whether the fly is living in the ideal conditions.
Prevent eggs from being laid by keeping the area clean. Cover trash cans and remove animal feces and standing water.
Remove adult flies through natural methods of prevention and elimination. Herbs, fans, and traps can keep flies away or kill them on contact.
Dealing with flies can be a pain, and there is often more than one underlying issue.
You’ll find lots more help for coping with fly problems in our section dedicated solely to flies. Click here.
