These pics are from June 12 & 13. Some species of ants have a symbiotic relationship with aphids. The aphids feed on plant sap and produce a sugary secretion called honeydew that the ants eat. The ants “milk” the aphids by stroking them with their antennae to stimulate them to produce more honeydew for them to eat. The ants will in turn guard the aphids from other predators.