Which rodenticide formulation is considered most effective for rat control in sewers?

The use of paraffin blocks as a rodenticide formulation in sewers is considered highly effective for controlling rat populations. One of the primary reasons for this effectiveness is that paraffin blocks offer a sturdy and durable option that remains highly palatable to rats, even in environments that are moist or subject to fluctuations in temperature, such as sewers.

Paraffin blocks are designed to withstand wet conditions without deteriorating quickly, ensuring that they remain available to rodents over an extended period. This characteristic means that rats have a continuous food source, which increases the chances of consumption and, consequently, successful control of the population. The solid form allows for targeted placement in burrows or along likely travel paths, which are critical factors in maximizing exposure while minimizing risks to non-target species.

In comparison, the other formulations, such as powders and granular baits, may not be as effective in wet environments like sewers, as they can wash away or become less appealing over time. Liquid baits could be appealing to rats but may also be less stable in sewer conditions, leading to reduced effectiveness. Therefore, paraffin blocks stand out as the best choice for rat control in sewers due to their durability, palatability, and effectiveness in such challenging environments.