I did a quick search on the Internet for pheromones.

Pheromones are chemicals released by an organism into its environment enabling it to communicate with other in its own species. There are many different types I soon learned.

Insect Pheromones

Alarm Pheromone.

When an ant is disturbed, it releases a pheromone that can be detected by other ants several inches away. They are attracted by low concentrations of the pheromone and begin to move toward the region of increasing concentration. As they get nearer to their disturbed ant releasing an alarm pheromone, their response changes to one of emergency and alarm. They run about to try to break up the disturbance that caused the alarm. Unless additional amounts of the alarm pheromone are released, it soon wears off. This ensures that once the emergency is over, the ants return to going about their business. Honey bees also have an alarm pheromone which is why if you get stung near a hive you can expect more bee stings really soon if you are not careful.

Leaving a Trail Pheromone

A trail pheromone is left by hands as they move about once they have found food. This trail attracts and tells other ants where to go to find the food. It is continually renewed as long as the food holds out. When the supply begins to dwindle, The trail Pheromone ceases to exist. The trail pheromone evaporates quickly so other ants stop coming to the site and are not confused by old trails when food is found elsewhere.

Sex Pheromones

Hundreds of pheromones are known with which one sex (usually the female) of an insect species attracts its mates. Many of these sex attractants - or their close chemical relatives - are available commercially. They have proved useful weapons against insect pests as they can be used to attract insects to a trap, and to confuse males so that they won