We all know that rich, earthy aroma of matured compost and how it can bring out the floral smells of our garden. But, that aromatic result is not always guaranteed, and sometimes a compost just stinks. Even a well-built compost bin can have a period of odor that can be unpleasant at best and could possibly attract unwanted guests.
I have seen the occasional fly and insects flittering above compost but is it possible for these piles to attract something bigger and less harmless? Are there things that, when added to compost, arouse the curiosity of unwanted pests? Let’s find out if animals can smell compost and what happens when they do!
Can Compost Piles Attract Animals?
Compost piles can attract animals, but the type of animal and the intensity of attraction depends on a variety of factors. The amount of carbon and nitrogen can influence if the compost smells from an imbalance of organic matter.
Garbage mixed with soil and high-rancidity foods like meat and dairy will produce odors that can attract larger animals. Composting improperly can be a danger in places where apex predators roam free.
The Department of Fish and Wildlife recommends locking trash and compost bins in cages in bear habitats. Wire mesh and wood can be used to add a layer that prevents wild animals from getting into your compost but learning exactly how compost attracts pests can prevent your kitchen scraps from becoming their food.
How Do Compost Piles Attract Pests?
The main way that a compost pile will attract pests and animals is through smell. Almost every creature is drawn to scent more intensely than a person is. Even if you don’t think your pit stinks doesn’t mean the critters in your yard are as nose-blind.
Most of the time, the odor-causing bacteria in compost are locked in the middle keeping the stench to a minimum. But there are times when the smell can be stronger, and then you could expect unwanted visitors.
Anytime you throw new, wet, still decaying materials onto a pile, they will give off an odor for a few days. Throwing new materials on top daily is a great way to attract rodents and bugs to your pile. Saving your waste and adding it once or twice a week and mixing it thoroughly at that time will reduce these pests.
When compost gets wet, the biology changes, and smells can leech out. These stinky puddles may invite unwanted critters hoping to find a meal or nutritious drink. The moisture can also kick start more decay leading to the familiar wet compost stench.
What Critters Do Compost Piles Attract?
| Pest Type | Likeliness of Attraction | How To Prevent |
| Bugs and Insects | Very Likely | Cover with fine mesh or seal |
| Rodents and Small Mammals | Very Likely | Build a wire mesh cage or lift off the ground |
| Birds and Reptiles | Somewhat Likely | Build wire cage |
| Large Mammals | Unlikely | Fence, strong mesh cage, sealed bin |
Compost piles can attract a range of creatures, but there are some that will be the most likely culprits. Birds and insects are very common sights on and around a compost. Compost piles do attract rodents often, and a tight, high-tensile wire mesh cage is a must to keep them out.
Some composts can attract bigger mammals, and in some areas, a compost pit is not advised due to predator dangers. In other areas, reptiles of all sizes might check out a pile to see what’s for dinner. You will want to do some research on the wildlife in your area to figure out what animals are coming for your pit.
For a broad overview of what animals your compost might attract and what to do if they show up, check out the section below!
Bugs and Insects
- Flies – Flies like to eat trash and food scraps, so it is no surprise that they would be the first likely visitors to your pile. Anytime you add new organic material to the pile, there is a chance you will attract flies and, consequently, maggots.
- Wasps – Like flies, wasps, yellow jackets, and some hornets may find meals in your kitchen scraps. Properly mixing scraps into the middle of a pile can keep most wasps at bay.
- Ants – While ants on their own are a plus for compost, if you have to deal with huge swarms of them moving into your yard, that’s a problem. Ants may be attracted to sweeter foods thrown in the compost and are likely to find areas where suspended decomposition is abundant.
- Centipedes – Another boon for compost health, centipedes are creepy, and a lot of people hate them. As long as your compost is healthy, the population of centipedes should self-regulate. If they get out of control, you can try reducing moisture in the pile.
- Spiders – Where there are flies, there are spiders. These guys will move in and all around your pile to catch the insects coming for dinner. Wear gloves when touching compost to avoid any accidental bites.
- Larva/Grubs – The larva and grubs of many soil-dwelling insects will make up a large portion of the living soil in your compost. These usually don’t cause problems, but some grubs and larvae turn into insects that can decimate your plants. Make sure if there seems to be a monoculture of larvae, to make sure they aren’t going to destroy your garden.
Rodents and Small Mammals
- Mice – These will be attracted to the seeds and scraps in your compost. When mice move into your pit, they can cause messes and lead to bigger problems. Composts that are elevated are less likely to be invaded than in-ground and ground-level pits.
- Rabbits – If a large part of your compost is yard waste and leaves, you may attract rabbits, squirrels, and chipmunks. They will eat what they can and try to burrow nearby; if your compost is near an old shed or structure, you have a higher chance of attracting small mammals.
- Moles and Voles – Compost that interacts directly with the soil can cause nearby vegetation to thrive. These plump plants have tasty roots for moles and voles. While not a danger to your compost, they can create holes that make it hard for you to access your pit with your ankles intact.
- Groundhog – While not as common as the other small mammals, groundhogs still visit piles if there are no better food options. The predators that stake out piles often take care of any groundhogs that stumble by.
Birds and Reptiles
- Small Songbirds – Little birds will eat the bugs and warms that are drawn to your pit. They add fertility and beautiful colors and sounds.
- Large Raptors – Eager for an easy meal, hawks, falcons, and eagles may use your pile as a hunting ground. Look up before accessing your pile to avoid a messy mishap.
- Medium and Large Scavengers – Vultures, crows, and buzzards can linger around a pile if there is meat stench. Be careful not to put rancid food in your compost.
- Small Lizards – Lizards love the soil diversity of compost. They also take advantage of the full sun on top of the pile. They pose no harm to you or your compost.
- Alligators – If you live near water and in an alligator habitat, then they may check out your pile. Call animal control if this reptile comes into your yard.
Large Mammals
- Cats – They like mice and the critters the pile attracts. It is common for cats to stop by a compost for some quick hunting before heading on their way. In some cases, they will add their own contribution by mistaking your pile for a litter box.
- Dogs – If they smell food, they may try to dig it out. This can cause a huge mess and attract more unwanted pests. Use fences or wire mesh to keep dogs out of your pile.
- Deer – A compost near the woods with a lot of greens may attract deer who are hungry for your yard waste. They can inadvertently cause damage to your yard so try to keep them out with fences and hedges.
- Bears – In bear habitat, they will smell your food and come investigate. Unless you want to meet a bear one morning, avoid composting or get a well-sealed one if you have these hibernating neighbors.