How to Get Rid of Maggots and Flies in Compost?

How to Get Rid of Maggots and Flies in Compost?

Fortunately, flies and maggots are uncommon visitors to hot composters like HOTBIN. However, when they show up, they can prove to be irritating little critters.

Their presence indicates that your HOTBIN is probably not up to hot composting temperature (104-140°F).

In order to eliminate flies and maggots from a HOTBIN, it is important to understand the types of fly that are found in and around your HOTBIN, appreciate how they may get occacionaly into the HOTBIN, and look at ways to get rid of them once and for all.

What types of flies are associated with compost bins?

House flies and fruit flies are the two main species of flies found in and around compost bins. Both thrive in a warm environment with access to plenty of fermenting and decaying material to eat, and lay their eggs in.

How can the flies and maggots get into a sealed HOTBIN?

When given the opportunity, flies will lay their eggs in any moist and warm decaying matter. They especially love kitchen containers with food waste, and when the lid is partially or fully open.

Once living amongst the food waste, female flies lay batches of between 120-150 eggs which will hatch within 72 hours.

Why does the number of flies in my HOTBIN seem to be increasing?

At the time of adding food waste into your HOTBIN, the eggs may not yet have hatched and so are not visible to the naked eye. If your HOTBIN is operating at non-composting temperatures of 68-77°F, it has the right ambient environment for the eggs to hatch and for the larvae to mature into adults and consequently, their population will grow.

How can I get rid of flies and maggots from my HOTBIN?

There are a number of preventative steps that you can take to minimize the chances of finding flies in your HOTBIN:

In the home you can:

1. Keep your food waste collection bins well covered to minimize the entry points and deprive them of a food source and breeding ground.

2. Ensure that any over ripe fruit is kept in the fridge or in the food waste collection bins so that flies do not infest the fruit – fruit flies in particular are attracted to the sweet sugars produced by the over ripe fruit.

3. Wipe up any spills on surfaces to remove any easy sources of food.

In your HOTBIN you can:

1. Ensure your HOTBIN is operating between 104-140°F.

2. Evidence from the World Health Organization has shown that fruit and housefly populations decrease at temperatures above 68°F and become undetectable at temperatures above 113°F. These hot composting temperatures, as well as helping to accelerate the decomposition process, also have the capability to destroy flies, larvae and eggs in the HOTBIN – so it’s win-win!

3. If you do have flies and/or maggots in your HOTBIN, you may need to check the temperature of your HOTBIN as they should not be able to survive above 104°F.

4. A quick check of the ‘how do I get to 104°F Check List’ might help detect the underlying cause of a cooler HOTBIN.

5. If, despite following the check list recommendations you are struggling to get your HOTBIN to reach 104°F, please email us at and we can help get you hot composting successfully.

6. Minimise the entry points to the HOTBIN by ensuring that the hatch and lid on the HOTBIN remain tightly closed and that the straps are in position (except when removing compost and adding new waste!) 7. Wipe the outside of your HOTBIN – a quick wipe over the area around the valve and the hatch can remove any residual odors or material and will further reduce the risk of attracting flies to the HOTBIN.

Warning:  We do not advise wrapping fruit and vegetable waste in newspaper before adding it to the HOTBIN. The newspaper will likely be visible in the final compost. This is  due to its high ligning content, that will likely delay the onset of decomposition to the wrapped waste and may also block airflow around the HOTBIN, causing your bin to turn anaerobic.

Why have I got flies hovering around the valve and hatch panel? Occasionally, you may find a number of flies hovering around the valve and/or the hatch panel, and unfortunately, there is not much that can be done to prevent this.

However, if they cannot find a food source or a place to lay their eggs... they will move away from the HOTBIN quite quickly.

Lastly... How can I keep flies away from the outside of my HOTBIN?

If the flies are consistently hovering around the HOTBIN and they bother you, you may wish to look at using a fly/insect spray which can be sprayed around the HOTBIN to repel them. The problem is, of course that the HOTBIN usually lives outside, therefore, the repellent will wash off as soon as it rains!

To conclude, if you keep your HOTBIN at composting temperatures between 104-140°F... you will most probably don't have this problem.


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