Maggots in compost – Should you be worried?

Seeing maggots in your compost can be an intimidating scene. Some people find it disgusting, while others think they are fascinating. Regardless of how you feel, should you be worried?

So are maggots bad in compost? No maggots are not bad for the compost. They can make the process much faster without any ill effects. However, they eventually turn into flies which may be troubling for many people. Though many simple solutions can help you solve this problem.

Whether you love them or hate them, once you have them in your compost you have to decide what to do about them. Lets dive further into this so you know why you should or shouldn’t get rid of them.

What are these maggots?

The maggots in compost generally consist of black soldier fly larva. Black soldier fly is one of the 120,000 species of flies existing in the world! They are harmless to humans. They don’t bite or spread diseases. They only thing they are guilty of is that annoying buzzing noise!

Life Cycle Of Black Soldier Fly

These flies have a brief life span lasting a few days. During that time, they have to reproduce, lay eggs and do maggot stuff!

Egg Stage – The female fly lay about 500 eggs on or near a compost pile, garbage bin or any other organic waste. These eggs are about 1mm in length and are creamy-white. In 4 days, they will hatch to form tiny larvae.

Larvae Stage – The larvae or maggots are dull and whitish coloured with leathery skin. They are plum, a little flattened and can reach the length of about 27mm and a width of 6mm! They have a head with projecting mouthparts. Maggots like to eat, and they eat a lot! And they keep doing it for about 14 days. In the larval stage, they go through 6 periods of growth before they turn into a pupa.

Pupae – Before turning into a pupa, the larva stops eating and seek out a dry and sheltered place where it can begin the pupation in peace. No feeding occurs during this part of its life. Its skin darkens, and in about two weeks, the adult fly emerges out of the pupa.

Adult Fly – The adult black soldier fly is about 16mm in length. The adult flies do not eat. They rely on fat stored during the larval stage. They also don’t enter our eating places seeking food. These flies don’t bite anyone eitherThey are not even responsible for transmitting diseases as they don’t have hair on their legs.

Why are there maggots in your compost?

The first thing to know is why are they in your compost in the first place. You have a clean home free from flies, then how did they manage to sneak in. Well, there can be several reasons for that.

  • The compost is too wet – If you oversaturate the pile with moisture, it creates anaerobic conditions. This results in a foul smell that attracts flies to lay their eggs.
  • You are adding the wrong things in compost – There are several things you are not supposed to add to your compost. These include milk and dairy products, meat, fish etc. They decompose badly and create a foul odour that draws flies.
  • The air holes are too large – For larvae to enter the compost, the flies have to somehow lay eggs in it. If the air holes on your compost bin are too large, flies can easily sneak in and do the job.
  • Improper Green to Brown ratio – If you added too many greens ( Vegetables, fruits etc.) compared to browns (dry waste like paper, cardboard, straw etc.), you are cordially inviting the flies to lay eggs in your pile.
  • The flies are unnoticed – These flies are not that big and can easily pass through cracks and openings around the compost bin. They can even enter through unwashed produce!

How to get rid of them

Keeping or not keeping the maggots is about personal preference. It all comes to how you feel about them. It is understandable if you think they are icky and may cause a fly problem later on. There are many simple things that you can do to remove them from the compost pile

  • Increase the ratio of browns

Larvae thrive in moist environments. The moisture is mainly provided by the greens you are adding to the compost. If you start adding more browns to the pile, it will dry the mixture and strip away a good part of their food source.

  • Put LIME into the mixture.

Lime increases the pH of the pile, making it more alkaline. The flies and maggots do not prefer this. The higher pH prevents the flies from laying eggs while eliminating grubs present in the compost.

You have to be very careful while adding the lime, though. Too high pH can ruin the usability of the compost. It is a good idea to know the soil’s pH you are going to use the compost on. 

Also, start by adding minimal amounts (1 cup of lime is sufficient for 25 cubic feet ).

  • Let the birds feast on them – You can spread out the compost and let the birds do the rest. It would be so much better if you have pet chickens. Several studies show the amazing effect of maggot based diet on chickens.

Before using these methods, you have to understand that whatever kills the maggots kills the worms in your compost as well. This is something you need to consider beforehand.

Benefits Of Maggots In Compost

If you are still doubtful whether or not to kill the larvae in your compost, you need to know all the great things they can do for you. As we have just discussed before, they don’t pose any danger to humans. They bring a host of benefits with them.

  • High-Quality Compost: They have the potential to enrich the compost with their rich cast. Maggots are an excellent source of oil and protein. The resulting compost has higher nitrogen content than the ordinary compost.
  • Excellent Feed: The larvae of the Black Soldier Fly is one of the richest sources of protein. They contain about 42% protein along with calcium and many amino acids. These larvae can be fed to the birds, livestock and fishes. You can even create a loop of providing the waste to the maggots and maggots to the animals that made it.
  • They Can Covert Many Kinds Of Waste – These grubs are designed by nature as scavengers. Their ability to decompose surpasses many worms. They can quickly and easily compost materials that ordinary worms won’t be able to do.
  • Much Faster than Worms – An average home produces about 1kg or 2 pounds of organic waste per day. Given the limited space of a compost bin, worms might not be able to process all that quickly enough, but maggots, on the other hand, takes care of it without any hassle. Several studies have compared the speed of grubs and worms, and maggots always emerge victorious in them.
  • Protect You from Harmful Species Of Flies – When flies are feeding, they secrete a chemical called synomone. This chemical alerts other species of flies to stay away! This is indeed, very effective. It has been found that synomone can reduce the number of houseflies by 95%.


When you see the maggots in your compost, you have nothing to worry about. You have Both options of keeping them or discarding them. And both options work well. But if you decide to keep them, you have nothing to lose (if you don’t hate them) and a lot to gain. You can expect to have your fastest compost so far. The resulting compost might look and smell a little different, but it is just as good or even better!


  • E.A. Ewusie, P.K. Kwapong, G. Ofosu-Budu, C. Sandrock, A.M. Akumah, E.K. Nartey, C. Tetegaga, S.K. Agyakwah,
    The black soldier fly, Hermetia illucens (Diptera: Stratiomyidae): Trapping and culturing of wild colonies in Ghana,
    Scientific African,
    Volume 5,
    ISSN 2468-2276,

Leave a Comment

Your email address will not be published. Required fields are marked *