What is the classification of rodenticides that requires ingestion multiple times to be lethal?

The classification of rodenticides that requires ingestion multiple times to be lethal is anticoagulants. These substances work by interfering with the normal clotting process in rodents. When consumed, anticoagulants prevent the synthesis of vitamin K, which is essential for blood clotting. Since the effects of these rodenticides do not produce immediate lethality—often taking several days to cause fatal internal bleeding—the rodent must ingest the bait multiple times over a period to accumulate enough of the active ingredient in its system to become lethal. This characteristic allows for more prolonged exposure, increasing the likelihood that the rodent will consume a lethal dose.

In contrast, acute rodenticides typically cause death after a single dose by inducing immediate physiological effects. Fumigants operate through gaseous formulations aiming to suffocate or poison pests, and organic does not refer to a specific mode of action related to rodent control. Thus, anticoagulant is the correct classification, highlighting the necessity of repeated ingestion for effective lethality in rodenticides.