Slugs have between two and four "noses," depending on how you define a nose.

• Slugs have two pairs of tentacles on their head. The upper pair has eyes and some sensory function, while the lower pair is used primarily for smelling. Inside the lower tentacles are tiny nostril-like canals connected to the brain that detect airborne chemicals, effectively functioning as noses for smelling

• Some sources count only these two lower tentacles as noses, giving slugs two noses in total

• However, because the upper tentacles also help perceive chemicals and some slugs have additional sensory openings on their body that connect to the brain, some experts consider these as additional "nose equivalents," which can bring the total to four or more nose-like structures

In summary, conservatively, slugs have two noses (the lower tentacles), but counting all sensory tentacles and openings involved in chemical detection, they can be said to have up to four noses