Not all of Chrysalis’ plans to divide and conquer pony society were grandiose, with some being much more obscure than others. A particularly creative one was to sneak boxes filled with unfertilized changeling eggs and branded as cereals to stores of towns surrounding Canterlot in advance of the planned invasion. The pheromones stored within, normally used to pacify captured prisoners were expected to at least halt some of the reinforcements that were bound to impede the assault.
 
The plan was unwittingly thwarted when a particularly dedicated pony ended up going after and hoarding the limited supplies. Vast quantities of pheromones accumulated made him particularly easy to track down and smuggle to an undercover Chrysalis, intent on getting the most out of the situation regardless.
 
NSFW followup: >>2100971