How many volts kill a rat? - briefly
A direct shock of roughly 100 V to 200 V can be fatal to a rat, depending on the current path and exposure duration. The exact lethal threshold varies with the animal’s size, skin resistance, and the waveform of the electricity.
How many volts kill a rat? - in detail
The lethal voltage for a rodent depends on the current that passes through its body, which is governed by Ohm’s law (V = I × R). Typical rat body resistance ranges from 500 Ω to 2 kΩ, varying with size, moisture of the skin, and contact area. Experimental observations indicate that a current of about 10 mA is sufficient to cause cardiac arrest in small mammals. Applying the resistance range yields a voltage interval of roughly 5 V to 20 V as the minimum level that can produce a fatal current under optimal conductive conditions.
Key factors influencing the outcome:
- Skin condition: Wet or broken skin reduces resistance dramatically, lowering the required voltage.
- Contact geometry: Larger contact surfaces increase current flow; point contacts concentrate voltage and may raise the threshold.
- Duration of exposure: Sustained exposure even at sub‑lethal currents can lead to thermal injury and eventual death.
- Species variation: Larger rats possess higher resistance, shifting the lethal voltage upward compared to smaller specimens.
Safety guidelines for laboratory work with rodents recommend using low‑voltage power supplies (below 5 V) and ensuring that any electrical stimulus remains under 1 mA to avoid unintended fatality. When higher voltages are necessary for experimental protocols, current‑limiting resistors and precise timing circuits must be employed to keep the delivered current within humane limits.
In summary, a voltage in the low‑digit range—approximately 5 V to 20 V—can be lethal for a rat when conditions allow the current to exceed 10 mA. Adjustments for moisture, contact area, and exposure time are essential for accurate determination.