For aluminum phosphide application in a main burrow, how should the tablets be placed?

• A. Place 1-2 tablets at the burrow entrance and loosely cover with soil.
• B. Place 2-4 tablets deep into a main burrow and plug openings with crumpled newspapers, then pack with loose soil; do not cover tablets with soil; inspect 24-48 hours later and retreat.
• C. Scatter tablets on the ground near the burrow.
• D. Use tablets on multiple alternative burrow openings.

Answer: (B)

When using aluminum phosphide, the goal is to generate phosphine gas inside the burrow system so the gas can spread through the tunnels and affect the target animals. Placing 2–4 tablets deep in the main burrow positions the source of gas where it will reach the most extensive network rather than just the entrance. Plugging openings with crumpled newspapers helps block surface air and encourages the gas to move through the burrow system rather than escape to the surface. Packing with loose soil around the area helps hold the tablets in place and maintain contact with the tunnel environment, but you should not bury the tablets completely by covering them with soil; they need access to moisture and air to release gas and diffuse through the tunnels. Waiting 24–48 hours before retreating allows time for the gas to act throughout the burrow network, after which you assess effectiveness and safety.