What is the main reason for placing traps along walls?

Placing traps along walls is primarily effective because rodents, such as rats and mice, have a natural instinct to travel along edges and boundaries as a means of safety and navigation. This behavior is often referred to as "thigmotaxis," where these animals prefer to stay close to surfaces to avoid detection by predators and to feel more secure while moving about in their environment. Setting traps along walls increases the likelihood that rodents will encounter the traps as they follow their habitual pathways, enhancing the effectiveness of rodent control efforts.

The other options provide different perspectives that could seem relevant, but they do not align as directly with the rodent behavior that prompts this specific trapping strategy. For instance, while traps can be less visible when placed along walls, that is not the main reason for this placement. Additionally, while avoiding non-target species and monitoring bait usage are important considerations in pest control practices, they are secondary to the primary behavior of the pests themselves. The key focus remains on aligning the trapping method with the natural tendencies of rodents for the best chance of successfully catching them.