The scent given off by each person’s unique immune system is the second-most important criteria (after disposition) women use to assess potential partners. Women are more likely to find people attractive who have with immune systems unlike their own.
You shouldn’t use Calvin Klein’s “Obsession” scent when you are on a Safari. Cheetahs, tigers, jaguars and other wild cats are attracted by it. Scientists use it to count the population of these animals better.
When it smells like rain, you’re actually smelling the ground.
Several astronauts after being on space walks have said space smells a little like a mix of “seared steak, piping-hot metal and arc welding smoke.“
Using a basic food-reward system, normal household dogs were trained to detect both lung and breast cancer with 90-100% success rate when checked by biopsy-confirmation, only by smelling patients breath. This also after only a few weeks of training.