Because of growing international trade, increasing numbers of invasive pest insects are being transported throughout the world. If they become established, invasive insects can have enormous impacts on agriculture, human health and natural ecosystems. However, it can be difficult to control them without causing further damage to the surrounding environment. Dr Robert K. Vander Meer of the USDA Agricultural Research Service studies the chemistry of pest ants, as it pertains to their behaviour and biological systems, with the aim of identifying efficient novel methods to monitor and control them.