Which rodenticide is highly toxic at low doses and is also used as a tracking powder?

The rodenticide that is highly toxic at low doses and is also used as a tracking powder is bromethalin. This compound is known for its potency, requiring only a small amount to be effective in controlling rodent populations. Bromethalin acts as a neurotoxin that impacts the energy production in nerve cells, leading to paralysis and death. Its use as a tracking powder creates an opportunity to see the movement of rodents within an area, which is helpful for understanding where the pest activity is most concentrated.

While warfarin and diphacinone are anticoagulants that require repeated feeding over time to produce a lethal effect, they do not fit the criteria of being highly toxic at low doses in the same manner as bromethalin. Additionally, zinc phosphide is typically used in a bait form rather than a tracking powder and has different toxicity implications. Thus, the unique characteristics of bromethalin make it the ideal answer to this question regarding high toxicity at low doses and its functionality as a tracking powder.