Olfactory probe

Olfactory probes, also known colloquially as "sniffer" droids, were droids, typically probe droids, that were equipped with an artificial "olfactory system" capable to detecting certain odors. They had many applications, such as helping law enforcement detect narcotics and helping hunters track a prey's scent; many cleaning droids and cooking droids also used artificial olfactory systems to assist them in their duties.