Just like a guy turning his head to savor the fragrance of a beautiful woman, sperm cells also pivot when they detect the alluring scent of an enticing egg. 
Research conducted in the United States has determined that some sperm cells can detect the scent of an egg even when it is diluted by 100,000 times.
“Sperm cells possess characteristics similar to the human nose,” stated Milos Novotny, a chemistry professor at Indiana University Bloomington.
Sperm cells contain olfactory proteins, akin to the receptors found in the nose. These proteins are located on the sperm membrane and signal the internal proteins to relay information.
“Sperm cells need to determine where that attractive chemical scent is coming from and adjust their trajectory toward it. They have a primitive recognition system, unlike some other bacteria,” Novotny explained.
Novotny and his team studied mouse sperm using a liquid pumping device that infused egg chemicals into a test tube and filmed the sperm’s movement. They found that many sperm were able to detect the chemical and swim towards it.
The research team is still unclear about which chemicals in the egg attract sperm, but they believe these chemicals are common across all mammal species. Therefore, the results could be applicable to humans.
In another study at the University of California, researchers also found that sperm quality declines with male age. This indicates that men, like women, have a biological clock, albeit slightly different. Men’s reproductive capabilities diminish gradually rather than abruptly, as seen in women.
