What is the most effective way to get rid of ants and other crawling insects?

First, seal entry points like baseboards, window gaps, and pipe entries with caulk or weatherstripping. Then apply a thin layer of food-grade diatomaceous earth along those paths—it’s not a poison but microscopic sharp edges that dehydrate insects. Keep it dry, as moisture ruins it. Skip vinegar sprays or peppermint oil, which only annoy ants temporarily.