A feed level sensor for a poultry feeding system is positioned within the drop tube of a control feeder of the feeding system. The sensor comprise a first light emitter/light detector pair to detect when the level of feed in the drop tube falls below a predetermined “empty” level and a second light emitter/light detector pair to detect when feed in the drop tube is at a predetermined “full” level in the drop tube. The sensor emits a “start” signal to activate a drive to deliver feed to the feeders along a feed line when it is detected that feed in the control feeder drop tube falls below the “empty” level and emits a “stop” signal to deactivate the drive when it detects that feed within the drop tube is at the “full” level.