A system ventilation and entrance adjustment for a beehive is provided. The system includes: a first panel comprising a first cutout and an entrance adjustment portion flanking the first cutout and a second panel disposed rearward of the first panel and comprising a second cutout. The first panel is slidable relative to the second panel. In a closed configuration the entrance adjustment portion blocks the second cutout to prevent bees from passing through, and in an open configuration the entrance adjustment portion either does not block, or only partially blocks, the second cutout to allow bees to pass through. The first panel and the second panel each comprise ventilation means. In the closed configuration and in the open configuration the ventilation means of the first panel are arranged to at least partially overlap with the ventilation means of the second panel to allow air to flow through the system.