As little as 100 molecules is sufficient to evoke a sexual response from a Bombyx male. Some flowers fool insects by using pheromones. Because of the odour the males believe the orchid flowers are females of their own species, and they try to copulate. Naturally, they are unsuccessful, but pollen grains of the orchid attach to them. The next time they try to copulate with an orchid flower, the pollen grains are transferred and they succed in pollinating the flower even if not in impregnating a female of their own species.
Elephant pheromones Even large animals can make use of pheromones.
Apparently, this substance lets bull elephants know that the time is right for romance. The human body secrets several compounds with strong smells, as well as compounds which can be transformed by bacteria into chemicals with a strong odour. Volatile aliphatic acids occur in the normal vaginal secretions of many primates, including humans. Many steroidal hormones and related chemicals have a noticeable odour, including chemicals called androstenones. In one experiment, some seats in a theater were sprayed with one androstenone.