Best rat poison 2023: Our pick of the most effective methods for dealing with rat problems

You’ve heard the scratching in the night, found food packaging and brickwork chewed, and droppings have begun to appear in specific areas of your home, garden or business premises. It all points to one ugly conclusion: you have rats. The key thing here is to act decisively – and quickly, as you’re going to need to get your hands on the best rat poison available.

Carrying an array of diseases that can be passed on to humans, including Leptospirosis or Weil’s disease, Salmonella, Listeria, Toxoplasma gondii and Hantavirus, rats are a danger to health and can even cause fires by gnawing through electrical cables. In fact, according to the British Pest Control Association via research carried out by the insurance sector, it is estimated that rodent damage to wiring is responsible for 25% of all electrical fires in buildings. What’s more, property owners have a legal obligation under the Prevention of Damage by Pests Act 1949 to keep premises rat and mice free, or, if rats pose a threat to health or property, to report infestations to the local authority.

Depending on the scale of your infestation issue, you might be able to deal with it on your own, but you’ll need to enlist the invaluable assistance of one of the professional-level rat poisons freely available on the market. Here we’ll run you through the different types of poison that are available, and suggest some of the best options of each type.

Best rat poison: At a glance

How to choose the best rat poison for you

What should I be looking for in a rat poison?

There are different varieties of highly effective chemical poisons legally available in the UK, as well as a selection physical rat traps, each type mixed into either wax- or grain-based baits, designed to appeal to a rat’s appetite. Some variants kill much more quickly than others, but do tend to cost more as a result of their potency.

Whichever you choose, though, they must be used in conjunction with lockable, tamper-proof bait stations (or boxes) to be legal in the UK. It’s essential to keep rat poison well out of reach of people, pets and other wild animals, so don’t be tempted to simply scatter the bait loosely on the ground.

We’ve looked at some of the best examples of each of the most commonly used and professionally recommended types here. All guarantee excellent elimination results, so it really comes down to personal choice and budget.

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How do I use rat poison with a bait box?

The method really is quite simple – secure your poison in the bait station and place it strategically against a wall where rat action is in evidence. It’s important not to clean the area first: rats are intelligent and naturally suspicious of changes to their environment, so a cleaned area will make them wary, not to mention the sudden appearance of bait boxes!

Rats tend to follow set routes, so once you’ve identified these via evidence such as dropping or chewed masonry or wood (a rat’s incisor teeth grow constantly, so they need to gnaw on things to wear their teeth down). They also prefer to move alongside walls for protection, so this is where you set your trap.

Once the rat ingests your poison it will normally return to its nest where it will die. The length of time and number of feeds this takes is dependent on the potency of your poison. With some, it can be up to 10 days, while other poisons can kill within 24 hours.

All the poisons recommended here are anticoagulants that thin the rat’s blood up to the point that the heart can no longer cope with pumping it, leading to a sudden heart attack. Gruesome as that may sound, it is actually a quick, relatively painless death.

Is rat poison dangerous to people?

All rodenticides can be toxic to humans when ingested, and also when inhaled or touched. Avoid contact as much as possible, use gloves when handling it, and always secure away safely from where children and domestic animals might access it. Always take time to read and adhere to the manufacturer’s instructions.

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The best rat poison to buy in 2024

1. Pest Expert Formula B+ Advanced: Best rapid-acting rat killer

Price when reviewed: £14 | Check price at Amazon

This is a rat poison that’s designed to get the job done quickly. Pest Expert’s Formula B+ rat poison is four times stronger than other rat poisons containing Bromadiolone and six times stronger than those containing Difenacoum, putting it at the maximum legal strength for pest poison.

Designed to be irresistible to rats, the formulation is made from top quality wholewheat grain to guarantee immediate appeal, and unlike other rat poisons that rely on multiple feeds, Formula B+ kills on initial ingestion.

Served up in 10x 100g sachets, the strength of Formula B+ means that it mustn’t be left where children or animals can get to it. Don’t be tempted to just scatter it around: it’s absolutely imperative that it be used in conjunction with a secure, lockable rat bait box, and crucial that it’s stored well away from inquisitive little fingers (or paws).

Its potency makes it suitable for both indoor and outdoor use, whether that be in homes, factories, farms and restaurants. If fast-acting no-compromise poison is required, Pest Expert Formula B+ is the right choice.

Key specs – Active ingredient: Brodifacoum; Dangerous to humans: Yes; Weight: 1kg

2. Roshield Wax Block Bait Rat & Mouse Killer: Best wax bait rat poison

Price when reviewed: £19 | Check price at Amazon

Roshield’s Wax Block Bait is a popular, professional-quality choice for use in lockable bait stations. It uses a formula of culinary grade wheat flour, blended with chopped wheat, other cereals and proteins, all bound together by edible waxes. This heady blend gives off a unique chocolatey aroma which, apparently, is impossible for rats to resist.

While that ‘unique chocolately aroma’ sounds like it might be appealing to young children too, Roshield have added denatonium benzoate, a highly bitter substance, to deter consumption.

The key poisonous ingredient here is Bromadiolone, a powerful anticoagulant that works by stopping the rat’s blood from clotting and, unlike some rat poisons is potent enough to kill from one feed rather than several days of bait station visits.

Roshield’s bait is suitable for domestic and commercial use, and it’s easy to use. Simply secure it in a bait box, place the box alongside walls inside or outside where there is known rat activity, and the rats will inevitably take the bait and return to their nest to die. Job done.

Key specs – Active ingredient: Bromadiolone; Dangerous to humans: Yes; Weight: 600g (2x 300g)

3. The Big Cheese All Weather Block Bait: Best cheap rat poison

Price when reviewed: £9 | Check price at Toolstation

The active ingredient in The Big Cheese’s Block Bait is Difenacoum, a chemical compound that’s been keeping rat populations down since the 70s. Similar to other poisons, this compound is a slow-acting anticoagulant known to attack several major organs as it does its work.

Price is a big selling point: the All Weather Block Bait costs under £7 for 30 blocks. It works with all tamper-proof bait stations and can be used both indoors and outdoors, as the moisture-resistant chemical formula keeps mould and fungi growth at bay while remaining highly palatable to rodents.

It’s not as rapid-acting as Brodifacoum or Bromadiolone – Difenacoum can take up to 10 days to kill rats – but once ingested the process starts immediately, so it’s slow but effective.

It’s still dangerous to both people and pets, so needs to be stored away safely and securely. It’s highly toxic to aquatic life, too, so should be kept clear of ponds and disposed of in an environmentally safe manner.

Key specs – Active ingredients: Difenacoum; Dangerous to humans: Yes; Weight: 300g

5. Elixir Gardens Rodex25: Best grain-based rat poison

Price when reviewed: £10 | Check price at from Amazon

Rodex25 is a whole wheat bait formulated with Bromadiolone, and it comes in individual grains rather than little waxy blocks. It also has one other unique element that sets it apart from other options: its colour.

It is hard not to notice Rodex25’s distinctive red hue, which is entirely the point. While with other baits you have to take it on faith that it is being fully ingested, the red dye mixed into the bait has the ability to turn rat droppings red, giving an unquestionable indicator that the poison is being eaten without having to actively check.

Arriving in 10x 100g sachets that are easy to dispense into bait boxes, Rodex25’s combination of taste adjuvants and sweeteners help make it irresistible to rats. Simply set your bait boxes, keep an eye out for red droppings and you’ll know it’s getting to work.

Key specs – Active ingredient: Bromadiolone; Dangerous to humans: Yes; Weight: 1.15kg

5. Ratkil Rat & Mouse Killer – Single Feed: Best cheap Brodifacoum-based rat killer

Price when reviewed: £7 | Check price at from Amazon

If you want the rat-eliminating power of Brodifacoum without spending the premium on Pest Expert Formula B+, then Ratkil is a cheaper option.

Rat poison containing Brodifacoum is the strongest that you are allowed to legally buy in the UK, so you can be assured of rat elimination from a single feed. As with the other baits featured here, Ratkil is made up of a formulation that rats find highly appealing.

Naturally, at this price, you get fewer Brodifacoum-based pellets than you do with other options found here (6x 25g), but this is enough to kill 40 rats, so one bag might just suffice. If you have a more serious infestation, you may want to consider going down the professional exterminator road instead anyway.

As always, a lockable, tamper-proof bait station must be used in conjunction with Ratkil. And, as ever, it’s essential to store any unused bait securely, and well away from children and animals.

Key specs – Active ingredients: Brodifacoum; Dangerous to humans: Yes; Weight: 150g