beta
Buying herbicide or insecticide in bulk from outside? But that's gonna take a LOT and humans seem like they would take advantage of that.
Since they're animal tower resident, don't they have bird species? Won't they be a good predator against locusts?
Maybe bait tactics? Mixing food and honey together and wait until the locusts swarm the food, and then burning them in one go? They do have that hamster wizard.