How long does rat poison take to start working? - briefly
Most rodenticides begin affecting a rodent within 12–24 hours after ingestion, with visible symptoms typically appearing after one to two days; full lethality usually occurs within three to five days, depending on the product and dose.
How long does rat poison take to start working? - in detail
The interval between ingestion and observable effects varies with the active ingredient, dosage, and the animal’s physiology. Anticoagulant rodenticides (e.g., warfarin, brodifacoum) typically begin to impair blood clotting within 12–24 hours, but lethal hemorrhage usually appears after 3–7 days. Single‑dose second‑generation anticoagulants may require up to 5 days before fatal bleeding occurs, while first‑generation compounds often act faster, sometimes within 48 hours.
Bromethalin, a neurotoxic agent, disrupts cellular energy production. Symptoms such as weakness, tremors, and seizures emerge after 2–4 days, with death often following within 4–6 days if the dose is sufficient.
Zinc phosphide releases phosphine gas after reacting with stomach acid. Toxic effects manifest rapidly, typically within 30 minutes to 2 hours, leading to respiratory distress and cardiovascular collapse within 24 hours.
Factors influencing onset include:
- Amount consumed – larger doses shorten the latency before critical symptoms.
- Species and size – smaller rodents metabolize toxins differently, often showing effects sooner.
- Health status – pre‑existing liver or kidney impairment can accelerate toxicity.
- Formulation – bait matrix (gel, block, pellet) affects absorption speed.
Observable signs progress from mild lethargy and reduced food intake to overt bleeding (anticoagulants), neurological disturbances (bromethalin), or respiratory failure (zinc phosphide). Mortality typically follows the peak of these symptoms; however, sub‑lethal exposure may result in prolonged illness without death.
In practice, expect a window of 12 hours to 7 days from consumption to death, depending on the specific rodenticide and conditions surrounding exposure. Monitoring bait stations and confirming removal of dead rodents within this timeframe helps assess efficacy.