Rodents - Rats & Mice

What are rodenticides? 

Rodenticides are chemical substances designed to kill rodents. They are classified into two categories: 

Anticoagulant rodenticides

Anticoagulants work by disrupting blood clotting in the rodent, causing internal bleeding and death. These rodenticides are either first generation, which means they require multiple feedings (e.g., warfarin), or second generation, which can be lethal after a single dose (e.g., brodifacoum).

Non-anticoagulant rodenticides 

Non-anticoagulants do not clot the blood and vary in their mode of action. Examples include acute toxins like zinc phosphide, which acts quickly but can have higher risks of non-target poisoning. 

What’s the difference between baits, pellets, and paste rodenticides? 

• • Baits: Rodent baits come in various forms, including blocks, grains, and soft bait sachets. Due to their food-like composition, baits use flavours and scents to lure rodents to consume them. Bait blocks are highly durable and suitable for outdoor use, particularly in damp or harsh environments, as they are less prone to decomposition. Grains or loose bait are suitable for indoor use where moisture is not an issue. 

• Pellets: Pellet rodenticides are small, easy to spread, and palatable to rodents. They are often distributed in areas where rodents forage like ceilings, wall voids, and sheds. An advantage of pellets is that rodents can carry them back to their nests, spreading the toxicant to other colony members. However, pellets are vulnerable to moisture and can break down in damp environments. Pellets are best used in controlled environments with limited access to non-target animals like pets and wildlife.

• Pastes: Rodent control pastes are highly effective in areas with food competition or where rodents have established nesting sites. Pastes are placed in tamper-resistant bait stations and are designed to be adherent, making them harder for rodents to avoid. They are useful in locations where rodents are accustomed to high food availability and are cautious of typical baits. Pastes can be applied in cracks, crevices, and wall cavities, making them ideal for indoor infestations where rodents are hard to reach. 

What are the best methods to control rodents?

The best method for controlling rodents will depend on the type of infestation, the environment, and the risk to non-target species. Rodenticide bait stations containing anticoagulant baits are a proven method for large-scale infestations, especially in agricultural settings or warehouses.

A combination of bait blocks and pastes in bait stations can effectively target different rodent behaviours. Bait blocks attract rodents seeking food, whereas pastes will attract those with a higher food competition that are less likely to consume typical baits. 

How do you use rodenticides safely?

Always follow label instructions and place rodenticides in areas that are inaccessible to children, pets, and wildlife. In outdoor settings, ensure bait stations are secured and weatherproofed. Inspect regularly for indoor infestations and promptly remove uneaten bait or dead rodents to prevent secondary poisoning of pets or scavengers.