It is often possible to smell when a pest infestation has occurred. For example, rodents can leave a musky odor, cockroaches produce an oily or musty smell, and bed bugs emit a sweet or musty scent. Foul or unusual odors can be an indicator of a pest infestation, and they often accompany visible signs like droppings, damage, or nests. Identifying these smells early can help in addressing the infestation promptly.