How long does mouse poison in grain take to work? - briefly
Most rodent anticoagulant baits begin killing within 24–72 hours after a mouse ingests the contaminated grain; faster-acting neurotoxic formulations can cause death in as little as a few hours. The exact timing depends on the poison type, dosage consumed, and the animal’s health.
How long does mouse poison in grain take to work? - in detail
Rodenticide incorporated into grain begins to affect mice shortly after ingestion, but the observable lethality varies with the active ingredient and environmental conditions.
The primary categories of grain‑based poison are:
-
Anticoagulants (e.g., brodifacoum, bromadiolone).
Absorption: 4–8 hours after eating.
Clinical signs: lethargy, internal bleeding.
Mortality: typically 2–5 days, sometimes up to 7 days if the dose is low or the mouse consumes only a small portion of bait. -
Zinc phosphide.
Absorption: immediate release of phosphine gas in the stomach.
Clinical signs: respiratory distress, convulsions.
Mortality: 30 minutes to 2 hours, depending on dose and grain moisture. -
Cholecalciferol (vitamin D₃).
Absorption: 6–12 hours.
Clinical signs: hypercalcemia, kidney failure.
Mortality: 3–5 days, with variation linked to the amount of bait consumed.
Factors influencing the time to effect include:
- Dose per gram of grain – higher concentrations shorten the interval to death.
- Bait acceptance – rodents that eat only a few grains receive sub‑lethal doses, extending the period before observable effects.
- Temperature and humidity – warm, dry conditions accelerate metabolic rates and gas release, reducing latency.
- Species tolerance – some wild mouse populations develop partial resistance to anticoagulants, lengthening the onset.
Monitoring recommendations:
- Check grain bins daily for dead or moribund mice.
- Record the time between bait placement and first mortality to gauge efficacy.
- Replace or supplement bait if no deaths occur within the expected window (48 hours for zinc phosphide, 72 hours for anticoagulants).
- Ensure non‑target species are excluded by using sealed storage and bait stations.
In summary, the interval from consumption of grain‑borne rodenticide to death ranges from under an hour for phosphide formulations to several days for anticoagulants, with the precise duration dictated by dosage, formulation, and environmental variables.