Hi Lisa, ants have a sometimes complex relationship with aphids. Most of the time they collect the sweet honey dew from them as food, sometimes they eat the aphids themselves and sometimes they actively "farm" them, moving them around to start new colonies and generally taking care of them. Many Australian ants tend aphids for the honey dew and probably eat a few (e.g. Iridomyrmex, Papyrius and many more) but I'm not sure if anyone has documented Australian ants moving aphids around to start new colonies. Here is a link to a nice article about it. Cheers, Jon https://www.cell.com/current-biology/pdf/S0960-9822(22)01077-6.pdf