Smelling tics manifest as an urge to smell something, sometimes without a specific pattern or when a specific thing is in view.
As sniffing is widely considered a vocal tic, the act of smelling could be also. This is despite no desire to make an audible sound.
Smelling tics can make a sufferer particularly self-conscious
This is particularly true when done in public, whether in school, at work or with family and friends.
There may be a desire to smell something particularly inappropriate, or when combined with an intrusive thought. Some tics are better described as Tourettic-OCD (sometimes abbreviated to TOCD), when a tic like urge is more obsessional in nature.
During the pandemic, many people reported losing a sense of smell. A smelling tic, without the ability to smell for periods of time, could increase stress levels.