What occurs when anticoagulant rodenticides cause death in rodents?

The option indicating that excessive bleeding leads to death is correct because anticoagulant rodenticides work by disrupting the normal blood clotting process in rodents. These substances inhibit the action of vitamin K, which is essential for synthesizing clotting factors in the liver. As a result, rodents develop internal bleeding, which can be fatal. Unlike some other types of poisons that may cause rapid effects like paralysis or instant death, anticoagulants typically have a delayed action. This allows the rodent to continue moving and feeding before ultimately succumbing to the effects of excessive hemorrhaging.

The other scenarios presented do not accurately describe the action of anticoagulant rodenticides. Rapid paralysis is not a characteristic effect; rodents may show signs of lethargy and weakness rather than paralysis. While some rodents may develop a resistance over time to certain chemicals, this is not the primary mechanism of death from these poisons. Lastly, the notion that rodents die instantly without symptoms contradicts the delayed-action nature of anticoagulants, since symptoms often develop after a period of time, leading to a slow demise rather than an immediate one.