Abstract: The present invention provides a delivery device for use in the control of a target animal species, the delivery device including: (a) a core containing a control agent for the target animal species, and (b) an impermeable coating enclosing the core, the coating being selected to provide exposure of the core in the gastrointestinal tract of the target animal species; wherein the coating of the delivery device has a hardness such that the coating is not readily breached upon mastication by a target or non-target animal species and further wherein the delivery device will not pass through a Tyler 5 mesh.