Abstract: A system for controlling a fly breeding apparatus, wherein the fly breeding apparatus comprises one or more enclosures for the containment of a population of flies; wherein the system comprises: one or more input devices, wherein at least one of the one or more input devices is a machine vision system or camera that is configured for imaging the population of flies, or a portion thereof, within at least one of the one or more enclosures; one or more output devices; and a control system; wherein, the one or more input devices, the one or more output devices and the control system are connected to enable the system to control and/or maintain at least one property of a status of the population of flies within the fly breeding apparatus. Methods for controlling a fly breeding apparatus and methods and apparatus for counting flies are also disclosed.