Silk Worm Pheromones
Chemical signatures that perform certain functions without the knowledge of the individual are termed as pheromones. These chemicals are unique to each species and they cannot be interchanged between species. In fact, some pheromones have been known to induce unwanted aggressive behavior in other species than that where it originated. The silk worm pheromone is one of the first chemical signature to be isolated and purified into its highly concentrated form.
When this pheromone was used on a silk worm, it was seen to dramatically increase the number of silk moths that got attracted to it. This increase was too enormous to turn a blind eye to and the same experiments were conducted with mammals. However, unlike worms and insects that are hardwired to respond to chemical substances, mammals are not hardwired and usually do not respond unless they are trained to do so. The chemicals used with mammals in experiments are then used with humans to see if there is any reaction from the opposite sex.