Drill bits (left to right): standard twist drill, countersink with pilot bit, countersink with tapered pilot bit
WARNING: Always read and follow the operating and safety instructions for any tool, attachment or accessory you use in the construction of a nestbox. Wear safety goggles to protect your eyes, gloves to protect your hands, and wear other appropriate safety items for protection, such as respirators to avoid dust inhalation and hearing protection when using loud power tools.