Slugs have two main "noses," which are the two lower tentacles on their heads used primarily for smelling. These tentacles contain tiny nostrils connected to the brain that detect airborne chemicals

. Additionally, slugs have an upper pair of tentacles that have eyes and may also assist in chemical sensing, and some species have sensory openings under their foot that contribute to smell perception

. Because of this, the count of "noses" can vary depending on the definition:

• Conservatively, slugs have two noses (the lower tentacles with nostrils)

• More broadly, if including all tentacles and sensory openings involved in chemical detection, slugs may be considered to have four or more nose-like structures

In summary, slugs have at least two noses, but some interpretations count up to four nose-like sensory organs due to their complex tentacle system used for smelling