Hello,

Pheromones were earlier known as intra species chemical messenger and are secreted by exocrine gland

These are intra specific chemical messenger released by animals into air to start specific response in another organism of the same species.

These are also called ectohormones or Sanio chemicals.

The term pheromone was coined by Karlson and Butenandt

These are volatile in nature and  are protein and lipid derivatives.

Long chain carbon pheromones are usually copulatory pheromones and short chain once are alarm pheromones.

These pheromones are species specific.

Hope this helps.