This was a fantastic read. The depiction of the ratfolk's need to breed and expand, Gritail's desire for recognition, and Verminax's calculating mind played together to set the stage for the old rat's discovery of a very dastardly weapon to use against humanity.
I really don't have any comments on the flow, except how well the story read. I especially enjoyed this line to help characterize Verminax: "his voice smooth as slime slithering down a wall."
As for the unconventional weapon, it's a great build up and reveal, one that I appreciated greatly.
Thank you for submitting this story for the writing jam!