Composting is a great way to reduce the waste you send to landfill and produce organic fertiliser for your plants. One of the biggest concerns around having a compost bin in the garden is whether it might attract pests or vermin. The short answer is yes, it can. But that’s why we’ve gathered advice to ensure you can build a pest-proof compost bin and enjoy all its benefits without the pain.
Why are pests attracted to compost bins?
The most likely pests to seek out you compost are rats and mice. They are a common part of a residential ecosystem and look for two things: food and shelter. This is why rodents are particularly attracted to compost heaps, especially in winter. It provides them with food and a warm, sheltered spot to sleep in.
Insects, however, are generally nothing to worry about in compost heaps. Worms, slugs, millipedes, spiders, beetles and more are regular guests. They are a crucial part of the decomposition process, so embrace the bugs!
Tips for deterring pests
Avoid putting any meat or dairy products in your compost, including fatty oils or bones. This would smell like a feast to rats.
Over autumn and winter keep your compost bin damp – this will help with the decomposition process and make it less attractive to rodents.
They also don’t like disturbance, so be sure to turn your compost regularly or give the bin a kick when you walk past!
Cover food scraps with dry leaves or soil in the bin to conceal the smell of decaying food.
Rodents are reportedly put off by the aroma of mint, so try sprinkling peppermint oil on your compost or planting mint nearby.
How to protect your compost bin
It’s very hard to completely protect a compost bin against vermin as mice can squeeze through holes as small as a penny, and rats can chew through almost anything. Compost bins are much easier to seal against invading pests than open heaps, so if you’re worried about rodents then they’re the better choice. Surrounding your bin with rocks and bricks can make it a bit more fortified.
If you have a plastic bin, this is easiest to seal. The best time is before you start using it as you’ll need to line the bottom with wire mesh. Ensure the holes are only small enough for bugs to get through, not burrowing mice.
If you have a wooden bin, again you’ll need to line the bottom and sides with wire mesh. Make sure this is sealed firmly round all the edges with no gaps.
Last resorts
Hopefully these tips will make your compost bin as unattractive to pests as possible. While the best defense is prevention, if you’re still experiencing issues then it might be time to look into pest control, such as traps.
Happy composting!
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George works in the Primrose marketing team. As a lover of all things filmic, he also gets involved with our TV ads and web videos.
George’s idea of the perfect time in the garden is a long afternoon sitting in the shade with a good book. A cool breeze, peace and quiet… But of course, he’s usually disturbed by his energetic wire fox terrier, Poppy!
He writes about his misadventures in repotting plants and new discoveries about cat repellers.
To get rid of mice & rats, it is important remove attractions such as unsecured rubbish and tidy your garden as to remove shelter. Then there is the decision about whether to use clinical or humane solutions, whether it be traps & poisons or ultrasonic devices. Primrose recommends ultrasonic deterrents as the lasting solution to your rodent problem, which acts as a permanent deterrent and allows you to avoid touching diseased carcesses.
Remove the Attractions
Key to keeping your home and garden pest free is to keep it tidy and free of rubbish. You can exterminate the existing rodents, but more will return if there is a source of food or shelter.
Rubbish should be kept in a secure bin, with the lid closed. Food shouldn’t be left out for other animals. Bird feed should be put up in specialised containers, and never on the ground. Similarly, tidying around the bottom of a fruit tree is worthwhile.
Remove the Habitat
Overgrown gardens provide a source of shelter in which many pests thrive. It is worth checking for holes that rodents will use as a nest.
Secure Your House
Rodents are both adept climbers and extremely nimble, able to enter through small cracks from the foundation to the attic. Hence, it is worth checking your brickwork as well as going into the loft.
Ultrasonic Deterrents
Ultrasonic devices are the most effective method to rid your house of rodents. Unlike traps and poisons, which only make room for new rodents, and at worst can act as a draw for new pests, ultrasonic devices function as a permanent deterrent. They also allow you to forgo learning about the different types of rodents and avoid handling dead, diseased carcasses.
Ultrasonic devices work by emitting ultrasound, which is inaudible to humans, but disconterting to rodents, who use such frequencies to listen for predators. The ultrasound causes them to leave the area, and is henceforth completely humane. Primrose has sold tens of thousands of units, with our best-selling model receiving nearly 2000 reviews, with a return rate of less than 2%. We also stock a battery operated model, perfect for lofts and outbuildings, which has an average rating of 4.2 from over 400 reviews.
Unlike with traps and poisons, it is best to install a device before sealing your house, leaving a space for the rodents to escape.
Rodent Types
If you are to use traps or poisons, learning about the different types of rodents can be useful.
Two species of rat are likely to enter your home, the black rat and brown rat (norwegian, cellar rat). The former is significantly smaller and more agile, and will infest the upper levels of buildings. The latter, by contrast, is much more likely to stick to the lower levels. With mice, the species most likely to enter your house is the adaptly named house mouse, which is even more agile than the brown rat.
Rattus rattus is the scientific name for the black rat, and Rattus norvegicus for the brown rat. Picture credit: Sponk licensed under CC BY-SA 3.0.
The different types can be identified by their droppings with the brown rat’s between 1.5-2cm, the black rat’s up to 1.5cm and mice less than 0.75cm. As mice are significantly lighter than rats, you are unlikely to hear them scurrying.
All rodents can survive on a poxy amount of calories, but mice can survive without water and will multiply quickly, producing up to 8 litters a year with a gestation period of 30 days. It is for these reasons that you can’t afford to wait, but have to act quickly.
Traps & Poisons
Unlike ultrasonic deterrents, it is important to seal your house before using traps and poisons, which can act as an attractant.
There are three types of traps: snap, electric and glue. Snap and electric traps are the most humane and usually kill instantly. Glue traps are extremely effective due to the attractants. Traps have an advantage over poisons in that carcasses can be found in the vicinity of the trap, while poisoned rodents can be hard to find.
Poisons have an advantage in that they can be used in communal areas, provided they are secured in bait stations, safe from pets and children. You should use different active ingredients for different situations. Alphachloralose is a must for mice, while for rats both difenacoum and brodifacoum can be used, although the latter shouldn’t be used in areas with non-target species.
For more information on poisons, please read our blog post here.
Rodents are initially wary of new introductions, so traps and poisons take time to take effect. Rodent tracker dust can be used to identify where rodents are coming from, which helps with the placement of traps.
Mouse poisons are often brightly coloured. Pictured are grains.
The best mouse poison is dependent on whether there is the opportunity for contamination with non-target animals and children and whether you are targeting a mouse or a rat. The active ingredient alphachloralose is always preferred with mice, while if you have rats difenacoum is preferred when non-target species are present, but brodifacoum is preferred when they aren’t. These ingredients are used to produce three types of baits: blocks, grains and paste satchels. The first is preferred in areas with non-target species as it is easily secured.
What are the active ingredients and which should I use?
Recommended in areas where non-target domestic or farm animals are present*
*Although Difenacoum is recommended where non-target animals are present, it is still a potent poison to mammal species. Therefore, it is vital that baits are protected from ingestion by non-target species. If you find a non-target animal has ingested the poison, seek medical advice from a vet immediately.
Racan (the poison experts) Say:
When compared to other multi-feed anticoagulant rodenticides, difenacoum has a good level of activity against the brown rat, and excellent levels of activity against mice. In comparison bromadiolone has a good level of activity against the brown rat, but only moderate levels of activity against mice. For this reason difenacoum was chosen as the active within the RACAN ‘HOME FRIENDLY’ range. This range will bring both rat and mice infestations under control, but due to the strength of the active this will take time, as the rodents will need to feed on several occasions to build up the level of active within their bloodstream to a lethal dose. Many customers will feel happier using this active as it is considered less of a danger to non-target species. It is also the best active for use in block baits as single feed baits in this formulation would offer a high risk to non-targets.
Extremely toxic to all mammals and therefore is essential that it is kept locked away from non-target animals. Bait boxes are strongly advised.
Racan Say:
With the restrictive changes brought in on active concentration, we thought it was sensible to give amateurs the opportunity to use single feed baits if they wish. Brodifacoum offers an excellent level of activity against the brown rat, being a significantly stronger anticoagulant active than difenacoum. This therefore is the active of choice in our single-feed anticoagulant RACAN ‘FORCE’ range. A rat will reach a lethal dose from one standard feed of this poison and so the results are seen very quickly. It is essential that all baits are well protected from non-target animals and the best way to achieve this is by placing the baits in an approved bait box.
Not affected by new legislation; proven to kill mice within minutes after one bite
Minimal secondary toxicity issues
Racan Say:
Within the RACAN ‘Rapid’ range we use alphachloralose which is part of the narcotic family and the most powerful mouse poison on the market. It is not affected by the new legislations as this only applies to anticoagulants. It is proven to kill mice within minutes with one bite of the product. It works by decreasing the mouse’s body temperature and sending it into a coma which it does not awake from. The active dissolves in the bloodstream and so (unlike anticoagulants) it has minimal secondary toxicity issues to non-target species. It is the speed of the onset of the active that makes it unsuitable for rats, as they feel the effect before they reach a lethal dose and therefore stop feeding. RACAN RAPID is a mouse only poison.
Unfortunately, other chemical controls such as zinc phosphide, calciferol and bromethalin are banned in the UK under EU law.
Should I use multi feed or single feed baits?
Multi feed baits cause the target species to gradually become sick over time. This can lead to the rat or mouse becoming disoriented and often will lead to them dying in an unreachable area such as under floorboards; this has obvious implications for hygiene.
Multi feed baits will by their nature take longer to work due to the requirement of the target species to return and feed numerous times before reaching a lethal dose.
Difenacoum a multi feed bait does have advantages however (as mentioned above) with non-target species. This is safer to use in areas where domestic pets or farm animals have access, but again should still be handled carefully and kept strictly contained and away from where non-target animals might ingest.
How do I know if I have rats or mice?
Mice and rats are best distinguished by the size of their droppings. Mice droppings are less than 0.75cm, while rats are significantly larger.
You’re are much more likely to hear rats than you are mice and are very unlikely to hear mice crawling.
Which active ingredient is best?
If you have mice only, alphachloralose is a no brainer. Brodifacoum is preferred in areas without non-target species, while difenacoum is preferred in areas with non-target species.
It is worth noting that both mice and rats have developed resistance to brodifacoum and difenacoum, although the latter remains effective against mice. As such uses of such ingredients is likely to exert a selectionary pressure, with larger and larger proportions of the rodent population possessing resistance to poisons. This is why we recommend ultrasonic repellers – the only lasting solution to your rat problem.
What type of bait should I use; grain, blocks or paste?
Grain Bait
Grain is the most common on the market and is easy to use by putting down around infested areas. Rodents will hold the bait in their cheeks and carry it back to the nest to feed others. Grain is generally effective due to being a part of a rodent’s natural diet. The difficulty with grain is preventing non-target species from ingesting the poison.
Bait Blocks
Bait blocks are advantageous due to their ability to be secured in bait stations or to surfaced using wire. Activity is easily monitored due to bite marks in the grain. They can be easily stored and transported with minimal risk of leaks or spillage. An ideal form of treatment in areas where keeping treatment away from non-target species is a concern. Their wax content makes them ideal for use in damp conditions. The one drawback of block bait is that they may not be as palatable as other alternatives and therefore could take a little longer to be effective.
Paste Sachets
Paste Sachets are highly attractive to rodents; made from ingredients such as cereals, oils, flour or fat and usually added flavouring. The packaging tends to be edible (like sugar paper). The sachet can be secured to a surface if required. Usually more powerful than traditional baits, they are mixed with liquid poisons to ensure every bite contains the active ingredient. They are particularly useful where rodents have refused to take other bait due to their attractive nature.
The type of bait is of secondary importance to the active ingredient. Grain bait is preferred in areas without non-target animals, while bait blocks are preferred in areas with non-target animals as they are easily secured in bait stations. Paste sachets are best used as a last resort, as their strong attractants can attract non-target species.
Where should I put the bait?
Rats:
For rats it’s important to identify areas of activity; faeces are usually a good indicator. Grain or Paste can be placed down burrows. Bait stations can be located along the runs between burrows and likely feeding points. Mice:
Bait should be placed in areas of high activity, again faeces is usually a good indicator. If you are struggling to locate the areas, see our tracker dust and UV torch which can be used to track footprints.
Why are the rats or mice refusing to take the bait?
Rats:
Rats can be wary of new objects in their surrounding, so it may just be that they’re not yet used to the bait station or bait being in their environment. Allow up to 2 weeks with the poison in place, after which you will need to move the bait to an area of higher activity.
Mice:
Unlike rats, mice are inquisitive and will explore any new objects in their surroundings. They will have no problem exploring a bait station or tray however if you find they aren’t attracted to the bait, you may find a more attractive type of bait could be used such as paste sachets. It is also good practice to move the station or tray each time you top it up, due to the inquisitive nature of mice this will actually entice them to explore.
How do anticoagulant poisons work?
Anticoagulant poisons work by preventing the liver from recycling Vitamin K. Vitamin K is essential to make the blood clotting agents which protect from too much bleeding. With enough exposure to anticoagulant internal bleeding occurs which kills the target species.
What does the law state about mouse poison?
Using brodifacoum is legal providing it’s put in a bait station. This helps protect both children and non-target animals. If you are to place stations in living areas, it is best to exclude pets to other parts of the house. Similarly, if a bait station is disturbed it is important to first search for a dead rodent, before letting children/pets in. With other poisons the greatest possible care should be taken to ensure non-target animals do not consume them. Unsecured poisons will leave you in trouble with the law.
How have changes in the law affected mouse poison products?
As of February 2018, EU law has slashed the maximum level of active ingredient from 0.005% to 0.003% for public use. Pack sizes have changed reducing bait blocks to a maximum 300g for rats and 150g for mice, with grain, pasta or pellet baits falling to 150g for rats and 100g for mice. This has originated from assessments showing that higher concentrations pose a risk to human health and the environment.
Is there a more humane or non-lethal way to get rats and mice out of your home?
We sell a range of electronic repellers which use ultrasonic and electromagnetic signals to deter rodents. Our best selling repeller comes with a money back guarantee and has 1800+ reviews.
Important: Always read the label. Always wear gloves when handling bait. If any rodenticide is ingested or you have any concerns, seek medical advice immediately and follow the first aid instruction on the product label.
Rats in the loft are a worrying sign for any homeowner due to their propensity to spread disease, damage property and steal food. Worse, rodents in the loft indicate that they have spread deep into the property, forming a network throughout your walls. To deal with rodents it is can be useful to first identify the type of rodent before addressing structural issues and then dealing with the rodents themselves.
Types of Rodent
In the UK, the most common type of rat is the brown rat, followed by the black rat a distant second. As omnivores, these rats will consume nearly anything and are fond of burrowing; hence, in urban areas they will enter properties for shelter and warmth, which usually occurs at the end of the summer and autumn when the weather starts to turn. Of the two, the black rat is incredibly agile and can often be found inhabiting the upper areas of buildings, while the brown rat is more likely to stick to lower levels.
The two rats can be distinguished by their length, weight, body proportions and facial features with the brown rat significantly larger (40 vs 24cm long) and heavier (500 vs 200g) with small ears and eyes and a slanted snout. By contrast, the black rat possesses large ears and eyes and a pointed snout. Unsurprisingly, its body is slender with its tail longer than the rest of its body, hence the difference in weight. The brown rat is the opposite with a thick body and tail shorter than the rest of its body.
Rattus rattus is the scientific name for the black rat, and Rattus norvegicus for the brown rat. Picture credit: Sponk licensed under CC BY-SA 3.0.
Of mice, the most common species found in UK homes is the house mouse followed by the closely related field and yellow-necked field mouse. The house mouse is particularly problematic as it can enter dwellings at any point of the year. Concentrated in rural areas, the field mouse will rarely enter homes, although may pose a problem to farm buildings. The house mouse can easily be distinguished from the field mouse by its colour with the former grey and the latter a sandy-orange.
A visual comparison of the field (L) and house mouse (R). Note the difference in colour. Picture credit: Hans Hillewaert licensed under CC BY-SA 3.0.
Significantly smaller than rats, mice can survive on a mere 3 grams of food a day and even go without water for significant periods. They are all excellent climbers and can multiply quickly. The house mouse, for example, can produce up to 8 litters a year with a gestation period of only 30 days. Hence, we recommend you act quickly to solve any rodent problem.
Safety Precautions
Rodents carry a wide range of diseases, some of which are deadly and others airbourne. Hence, other than wearing gloves and using a facemask, we recommend you air out any space before removing carcasses or excrements.
Detection
Rodents are usually identified by their droppings or the sound of crawling, scratching and gnawing, although can also be identified by chewed wires or pipes. In general, rats are more audible than mice and you are less likely to hear the latter crawling. Brown rat’s droppings are the largest between 1.5-2cm, black rat’s up to 1.5cm and mice less than 0.75cm. If you are having trouble locating your intruders, you can use rodent tracker dust to identify their comings and goings and aid trap placement.
Addressing Structural Issues
Rodents, along with other pests, can enter your property through small cracks in the brickwork. They can enter your property through climbing shrubs and trees, and black rats may enter your loft directly. Hence, we recommend you seal any cracks with insulation foam and cut back overgrown plants. Rodents will often first take interest in a home due to overgrown gardens and easy access to waste. Hence, it is important to keep your rubbish tidied away.
Solutions
Primrose has over 10 years’ experience developing pest control products and offers a large range of solutions to rodent infestations, divided into clinical and humane solutions. Of all our products, we’d recommend ultrasonic repellents. They work by emitting ultrasound waves, inaudible to humans, but painful for rodents, who use this frequency to listen for predators. Disturbed, they will move out of the vicinity of the sound. We offer both battery and mains powered repellents, of which the former can be useful if you do not have a socket in your loft.
Clinical solutions include mouse and glue traps. In the vast majority of cases a mouse trap will kill a rodent instantly, so they are humane in a sense. Glue traps are extremely effective and work great in tandem with conventional traps. However, the major problem with clinical solutions is that they rarely provide a long term solution as killing existing rodents simply makes room for new ones. Hence, we recommend you start with any ultrasonic repellent, before moving onto these solutions.
If you are using ultrasonic repellents, it is important to first give it time to work and then seal cracks in your property to allow room for the rodents to escape. If you plan to just use just clinical solutions, it is important to first seal your property. Ultimately, it can be useful to use all three solutions in tandem that have proven to be highly effective in dealing with the worst problems, and significantly cheaper than relying on professional pest control solutions.
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Jorge works in the Primrose marketing team. He is an avid reader, although struggles to stick to one topic!
His ideal afternoon would involve a long walk, before settling down for scones.
Jorge is a journeyman gardener with experience in growing crops.
George works in the Primrose marketing team. As a lover of all things filmic, he also gets involved with our TV ads and web videos.
George works in the 
Jorge works in the Primrose marketing team. He is an avid reader, although struggles to stick to one topic!
