How do rat bait bricks work? - briefly
Rat bait blocks contain a slow‑acting anticoagulant that leaches onto the rodent’s mouth when it gnaws the solid matrix, enters the bloodstream, and prevents blood clotting, causing death within several days. Effective control requires placing them in concealed, high‑traffic areas where rats are likely to feed.
How do rat bait bricks work? - in detail
Rat bait bricks are solid, compact formulations that combine an anticoagulant poison with a carrier matrix. The matrix, typically a blend of wheat flour, cornmeal, or other digestible binders, gives the product a brick‑like shape that resists disintegration in humid environments. When a rodent gnaws on the brick, it creates small chips or shavings that are readily consumed. These fragments contain a precise dose of the active ingredient, most commonly bromadiolone, difenacoum, or chlorophacinone, which interferes with the animal’s vitamin K cycle. By blocking the recycling of vitamin K, the poison prevents the synthesis of clotting factors II, VII, IX, and X, leading to internal hemorrhage and death after a delayed period of 2–7 days. The delay allows the poisoned rodent to return to its nest, increasing the likelihood that other members of the colony ingest the toxin through secondary exposure or shared food sources.
Key functional elements of the brick include:
- Controlled release: The carrier material dissolves slowly in the rodent’s saliva, ensuring a gradual intake of the anticoagulant.
- Palatability: Flavorings such as peanut butter, cheese, or soy enhance acceptance, while the solid form prevents premature spoilage.
- Dosage stability: Manufacturing processes embed a fixed amount of active ingredient per unit weight, guaranteeing each bite delivers a lethal dose for a typical adult rat (approximately 30 mg of bromadiolone for a 300 g animal).
- Safety features: Low‑odor, non‑volatile composition reduces accidental exposure for non‑target species; many products also incorporate bittering agents to deter pets.
The mode of action proceeds through three stages:
- Ingestion: The rodent consumes chip fragments while gnawing.
- Absorption: The anticoagulant is absorbed through the gastrointestinal tract into the bloodstream.
- Physiological disruption: Inhibition of vitamin K epoxide reductase halts clotting factor production, resulting in progressive internal bleeding.
Secondary poisoning occurs when a predator or scavenger consumes a dead or dying rat containing residual toxin. Because the anticoagulant remains in the tissues for several days, secondary exposure can be lethal to birds of prey, feral cats, or other mammals. Consequently, placement guidelines advise using bait stations that limit access to target rodents while protecting non‑target wildlife.
Effective deployment relies on strategic positioning near walls, burrows, or travel routes, maintaining a density of one brick per 100 sq ft in high‑infestation zones. Regular monitoring, replacement of depleted bricks, and adherence to local regulations ensure sustained control while minimizing environmental risks.