Final answer:
d. Treating ants as a forage is the least effective way to treat for ants.
Step-by-step explanation:
The least effective way to treat ants is d. treating them as a forage.
This method involves allowing the ants to forage freely without taking any specific action to eliminate or control their population. Treating ants as a forage does not address the root cause of the ant infestation and does not prevent them from causing further damage.
Instead, more effective methods like caulking cracks around the foundation, removing food sources, and treating perimeter ornamentals for aphids or scale insects should be employed to control ants.