1) GENETIC VARIATION- there are two types of ants: fire ants the ones who bite to get a grip then sting (from the abdomen) and inject a toxic alkaloid venom and a black garden ant, the ones that just bite and spray acid on the wound.
2) OVERPOPULATION & SELECTIVE PRESSURES- a single army ant queen can lay up to 300,000 eggs and unfertilized eggs grow into male drown ants.
3) DIFFERENTIAL SURVIVAL AND REPRODUCTION- living in any area antilions often eat ants underground. but in an area with moist dirt/sand black garden ants are popular and red fire ants are popular in dry dirt areas. ants are the most common insect antilions would eat but only the black garden ants. antilions wont eat red fire ants because the red ants actually prey on spiders, scorpions, etc.
4) CHANGES IN THE GENE POOL- if most of the black garden ants are being eaten in mostly every area then the red fire ants population will increase because they only live in dry areas but the black garden ants population will decrease but not be completely gone.