In certain areas of California, which species of rats show resistance to anticoagulant bait?

The correct answer is that roof rats are known to show resistance to anticoagulant bait in certain areas of California. This resistance occurs due to genetic adaptations that allow certain populations of roof rats to survive exposure to anticoagulant rodenticides, which are commonly used for rodent control. These anticoagulants disrupt normal blood clotting processes, leading to eventual death in susceptible rodents. However, when selective pressure is applied through the use of these baits, some individuals within populations may develop resistance, allowing them to thrive and reproduce despite exposure to the poison.

Roof rats, which are commonly found in urban and suburban environments, tend to be more adaptable and capable of developing this resistance compared to other species such as brown rats or Norway rats. Understanding the dynamics of resistance in roof rats informs pest management strategies and highlights the importance of using an integrated pest management approach that considers alternative control methods in resistant populations.