What is the recommended maximum depth for applying tracking powder for mouse control?

The application of tracking powder for mouse control should be kept to a maximum depth of 1/4 to 1/2 inch. When applying the powder, it's important to use a shallow layer so that mice can easily come in contact with it. A depth of 1 1/6 inch exceeds this recommendation, which could reduce the effectiveness of the tracking powder. If the powder is too deep, it may not remain accessible for the mice to groom themselves and inadvertently consume it, which is the primary means of control.

The other options suggest applying the powder at depths that either meet or exceed best practices. Specifically, a depth of 1 inch or 2 inches is too deep and can hinder the rodents from coming into contact with the pesticide effectively. Thus, the 1/2 inch depth is generally acceptable, but the suggested maximum application depth for tracking powder is best maintained at or around 1/4 inch for optimal results.