What’s Crawling in Your Compost? Top 8 Compost Critters you might find in your Compost Pile
Even in a hot composting environment like the HOTBIN, you’ll find a myriad of composting critters in your heap that play a beneficial role in breaking down food and garden waste. These creatures – from worms to woodlice – may sometimes seem like uninvited guests but are actually aiding the composting process and the finished product. Discover 8 composting critters that you may find in your compost bin and how they aid the decomposition process helping to produce high-quality, peat-free compost for your garden.
Why Are Composting Critters Important?
- Aid the breakdown of organic waste
- Support microbial activity and airflow
- Help indicate the health of your compost pile
Learn more about bacteria and micro-organisms in soil
Meet the Composting Critters in Your HOTBIN
1. Worms - Compost’s Natural Recyclers
The presence of worms in a compost heap is usually a sign of a healthy, thriving composting environment. In most cases, you'll spot the brandling worm, which is particularly well-suited to composting due to its ability to digest organic matter efficiently.
Worms may be found inside the HOTBIN, but they don’t favour really hot composting conditions, so you may find them around the lid as they try to escape the high temperatures. Typically, any worms that do find their way into the heap tend head for the cooler layers at the base where they contribute to the breakdown of waste material through digestion, producing nutrient-rich worm castings that enrich your compost.
When it comes to harvesting it is not uncommon to find worms in the bottom layer of material in the HOTBIN, helping to mature the compost.
HOT TIP: When adding compost to your borders or beds, any remaining worms will happily move into the soil and continue helping with decomposition, improving your soil structure.
2. Ant’s – Just a Nuisance!
Can often be the source of much frustration, ants can help aerate a compost pile although their presence is usually an indication that the contents of your HOTBIN might be too dry. This can be rectified by giving the material a mix to disturb the nest and then adding nitrogen-rich "greens" like grass clippings or food waste to restore the balance or moisture.
3. Woodlice – Naughty or Nice?
Woodlice thrive in warm, moist environments. They’re excellent decomposers that feed on decaying organic matter, aiding the composting process.
4. Slugs – The Good, the Bad and the Ugly!
There are only a small number of slugs that are classified as garden pests - controversial we know! However there are other species of slug (like the great black slug) that can help break down waste in the early stages of decomposition. Despite its misleading name, this slug varies in colour from grey to a striking orange.
Slugs frequent compost piles often in the early stages of decomposition, they will digest waste before it’s broken down further by bacterial activity as the pile heats up.
A large slug population may mean your compost is too wet - balance with carbon-rich "browns" like shredded paper or cardboard to help absorb some of the excess moisture.
5. Millipedes and Centipedes – So Many Legs!
Often confused, millipedes and centipedes are quite different in both appearance and behaviour—but both can be frequently found in compost piles. Millipedes are slow-moving decomposers that feed mainly on decaying plant matter. As they munch through the waste, they create tiny tunnels that help air and microbes circulate, boosting the composting process.
Centipedes, on the other hand, are fast-moving predators. They don't feed on waste directly but instead hunt other compost dwellers like insects, slugs, spiders, and even worms. This might sound alarming, but they’re part of a natural food chain and indicate a healthy composting ecosystem.
Both species are drawn to moist environments as their skins lack a waxy outer layer, making your compost pile the perfect spot. However, an abundance of centipedes could be a sign that your compost is too wet.
6. Spiders – Natures Pest Control!
While spiders don't contribute directly to breaking down organic matter, they play a valuable supporting role in your HOTBIN composting ecosystem. They’re hunters, not composters, feeding on insects like flies, mites, and other small critters that might otherwise become a nuisance.
Their presence in your compost heap is a good indication that there’s a buffet of prey around—and that your compost is teeming with life. Don’t worry, they’re not there to cause trouble. In fact, their webs help keep the fly population in check.
7. Flies and Maggots – Compost Friend or Foe?
Those species most often found in compost piles are those whose larvae feed on either the manure or the kitchen scraps found there.
Files only become a nuisance in a compost heap/pile if they are in large number as this could indicate that there is too much moisture in your compost bin which is a perfect breeding ground for maggots.
To avoid this:
- Add carbon-rich material like paper or cardboard to soak up excess moisture.
- Mix new food waste into the existing contents instead of leaving it in layers.
- Always keep your food caddy lid closed to avoid flies laying eggs, which could then end up in your bin.
8. Fruit Flies – They Just Love Overripe Fruit!
Fruit flies are small, fast, and often the most irritating critter in a compost pile. They’re usually found hovering around fermenting fruit such as banana peels, apple cores, or citrus rinds.
Although they are neither friend nor foe in the compost pile, fruit flies can be annoying, readily flying up a nostril every time the lid is lifted or the pile is disturbed.
Fruit flies don’t break down material, and they’re not particularly helpful or harmful. They're simply there for a free lunch.
How to reduce fruit flies in your HOTBIN:
- Mix fruit waste thoroughly into the compost rather than leaving it on top.
- Again, don’t leave fruit scraps exposed in the food caddy—keep the lid on tight!
- Add a layer of shredded paper or cardboard to help trap smells and moisture.
FAQs About Composting Critters
Are bugs bad for composting?
Not at all—most bugs improve composting by helping to break down organic matter.
Why are there so many insects in my HOTBIN?
It could indicate moisture imbalance. Depending on the insect mix in some dry or wet material.
How do I stop flies and fruit flies from becoming a problem?
Mix new waste in well and avoid exposed fruit scraps.
My HOTBIN Has Lots of Worms – Has It Stopped Working?
Worms are beneficial to the composting process and often live in the cooler base helping to break down the organic matter further.
Learn more about how HOTBIN works