The cockroach infestation smells really bad and awful. Even if your one room has an infestation, it is going to fill up your whole house. Some of the main reasons for this infestation are their urine, feces, pheromones, and dead bodies as well. This oily liquid, oleic acid, from dead roaches contributes to the musty smell and gets worse over time. Have you ever smelled rotten and mold food? Cockroach infestation smells exactly the same as that. But, sometimes it also has a sweet odor like maple syrup. One of the main reason for these smells are cockroach poop and urine. Infested homes, especially areas behind the cabinets, under sinks, or the inner part of the kitchen, smell strongly due to German cockroaches. https://safepestsol.com/cockroach-infestation-smell/