Left photo - bait testing efficacy trial showing YCAs drawn by the sugary hydrogel containing insecticide. Right photo - YCA worker carrying hydrogel crystal (saturated with sucrose containing the insecticide) towards the nest located in an above-ground cavity of a kou tree (Cordia subcordata) at Johnston Atoll NWR. Once in the nest, the bait will be shared with queens, their developing brood, and other workers. December, 2015.