One of the threats to the ferret population is the Sylvatic plague, a bacterial disease transmitted by fleas. The plague is lethal to both ferrets and prairie dogs, who provide ferrets with a source of food and tunnels for shelter. An oral Sylvatic plague vaccine has already been developed and approved for prairie dogs and ferrets, and the USFWS suggests that drones will be able to deliver the vaccine at a significant scale.
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The USFWS has constructed a device that can shoot peanut-butter covered M&M's in three different directions, according to The Guardian. The device will be strapped to drones that will fly over the UL Bend National Wildlife Refuge, delivering the vaccine to the animals below, who, according to Machett, think the candy is "delicious."