Before one can make mead, one must first have honey! Farmers on both sides of the Mitgardia/Avalonia boarder keep bees to pollinate their crops and produce honey.
During the Drow incursion in Avalonia, western Mitgardian army officials ordered hundreds of shafts dug to the bedrock for the early warning devices perfected by the Kaliphlinites. These devices were drums placed at the bottom of each shaft that, when the ground vibrated, beat seemingly of their own accord. If one was near enough to hear, the alarm could be raised and a Drow sneak attack from underground would be far less sneaky. Although no Drow tunneled to Mitgardia during the crisis, the drums were manned again on Elon Chorian’s command to listen for Amortug dwarves tunneling in the opposite direction.
This MOC was inspired by the Mythbusters episode where they test the rather dubious myth that in the middle ages Chinese military engineers used drums to sense vibrations in the ground caused by enemy tunneling. Apparently, it's plausible... Link: http://www.discovery.com/tv-shows/mythbusters/mythbusters-database/chinese-sonar-invasion-alarms/