It's important to be able to locate your queen amidst the buzz of a large colony. This queen marking tube makes it easy to mark your queen and track her once she enters a colony. The plastic construction makes it easy to see your queen, and the screened bottom makes it a breeze to mark her! Just place your queen in the tube and gently move her towards the screen with the plunger. Once her back is against the screen, mark her with a pen and then release her.