The answer to 'why is my bed bug odor' is that bed bugs release a distinct, musty odor when they are present. This odor is caused by the chemicals and pheromones they release, which can be detected by both humans and dogs trained to identify bed bug infestations.
The bed bug odor is often described as a sweet, musty, or coriander-like smell. As the bed bug population grows, the odor will become more pronounced. This odor can be an early sign of a bed bug problem in your home, even before you start seeing the bugs themselves.