How did leaf-cutting ants develop their farming techniques?

Leafcutter ants are mushroom farmers. They cut leaves and haul them back to their underground colony. Other worker ants reduce the leaves to mulch. This mulch is the compost on which the fungus grows. Leafcutter ants use this fungus for food. However, this fungus can be destroyed by mold.

Leafcutter ants are also pharmacists. The worker ants that are tending this fungus farm use a special antibiotic to kill the mold. This antibiotic, actinomycetes, is carried on the ants’ bodies and scattered about as they tend the farm. 

Leafcutter ants are also treasure hunters. Because this antibiotic is needed, other ants go out and look for it in the soil and bring it back. They have to find the right antibiotic in the right soil to protect their fungus and then walk around the farm spreading the antibiotic. 

How did they know how to cut and compost the leaves in order to make a mulch to feed the fungus? How did they know that a certain soil contained exactly the antibiotic that would kill that specific mold? How did they know to have the worker ants carry this antibiotic on their bodies and to drop it off as they tended to the farm?

God brought it all together for the great pleasure of seeing our wonder when we discovered this and other marvels He has created. He preprogrammed these many characteristics into the ant’s DNA. 

(Source: Inspired Evidence Von Vett & Malone, Creation Science www.Create.ab.ca/Superior-Farms/)