What pest control method is effective against fleas in outdoor settings?

In outdoor settings, using insecticide spray is a highly effective method for controlling fleas. This approach allows for the direct targeting of flea populations in the environment where they thrive, such as in grass, soil, and shaded areas where pets may frequent. The active ingredients in insecticides can provide immediate knockdown of adult fleas and often have residual effects that can kill newly emerging fleas from eggs or larvae for an extended period.

Other methods, while useful in certain contexts, do not offer the same immediate and long-lasting impact against flea infestations outdoors. For instance, soil treatment may help in a more general pest control scenario but may not specifically target fleas. Physical removal, such as vacuuming or brushing pets, can help reduce the flea population but is not comprehensive and often requires additional methods for effective control. Traps can be useful to monitor flea activity or reduce numbers, but they are often limited in capturing fleas and do not significantly impact the broader population in outdoor areas. Thus, insecticide spray stands out as the most efficient method for outdoor flea control.