Ants are probably tending sucking insects, not causing the damage themselves.
When you say "eating" do you mean the leaves are chewed up? -- that would typically be caterpillars or beetles, sometimes slugs or snails.
How "small" are the white "blobs" -- tiny might be mealybugs, bigger and looking like bird droppings might be swallowtail butterfly caterpillars.
Photos and knowing your location would help to ID.
Learning never ends because we can share what we've learned. And in sharing our collective experiences, we gain deeper understanding of what we learned.