The human nose can detect a trillion odors, and it appears that scents influence our behavior. According to a new study, humans produce chemical cues that communicate our gender to the opposite sex, and just a whiff of these compounds influences our perception of someone as masculine or feminine, iflscience.com reported.

"Our findings argue for the existence of human sex pheromones," Wen Zhou of the Chinese Academy of Sciences says in a press release. "They show that the nose can sniff out gender from body secretions even when we don't think we smell anything on the conscious level."

Specifically, what we’re smelling are active steroids: androstadienone in males and estratetraenol in females. Androstadienone, which is found in semen and armpits, have been showed to improve women’s moods, but not men’s. Estratetraenol, first identified in female urine, has similar effects on males.

To figure out if those chemicals are acting as sexual cues, Zhou and her colleagues asked males and females to watch “point-light walkers” (PLWs, pictured) move in place on a screen. These consist of 15 dots representing the 12 major joints in the human body, plus the pelvis, thorax, and head. You can see examples of the PLWs in this video. Each participant watched seven digitally morphed gaits, one at a time and in random order. They had to judge whether the walker was a male or female.

Additionally, they completed that task while being exposed to androstadienone, estratetraenol, and a control solution -- all of which smelled like cloves -- each on a separate day.

 The results revealed that smelling androstadienone biased heterosexual females (but not males) toward perceiving walkers as more masculine. However, smelling estratetraenol biased heterosexual males (but not females) toward perceiving walkers as more feminine.