A packaged chemical pad may include an air tight protective packaging surrounding a chemical pad. The chemical pad may include a semi-permeable membrane and a chemical composition disposed in the semi-permeable member. The chemical composition may automatically, on activation by oxygen following the removal of the protective packaging, generate an infra red heat and water vapour. The activated chemical pad, when positioned in an insect trap, may maintain a temperature at a pad surface of between 20° C. and 40° C. and a relative humidity of at least 10% above an ambient humidity for an operating duration of at least 8 hours.
