Okay, see this underneath the normal menu with Breed/Sell/etc?
By completing these, your Throdma will gain a Pheromone of the related type. Battles won = warrior, battles lost = defender, islands = scout, and resources = harvester. Each worker will only ever get one of these (meaning once you use it, you can’t get another)
To use these, go to your recently born Throdma and look in the corner. (I don’t know if I’ve ever actually done this myself, so I’m trying to remember). There should be three spots to select other Worker Throdmas. If you assign a Throdma with an available Warrior pheromone to give its Warrior pheromone, then the baby will grow up to be a Warrior grade 1. This works for the other Pheromone types, and up to grade 3 by assigning another worker with a pheromone available.
Again, each Worker can only give one of each type. Also, it all has to be one type. You can’t give a baby a Warrior pheromone and a Cout pheromone.