Yes, DEET (Diethyltoluamide) is highly effective at repelling biting midges, including the notorious "Highland Midge" found in Scotland and various "no-see-ums" in coastal regions. In 2026, DEET remains the gold standard for insect repellents because it interferes with the midge's ability to "smell" the carbon dioxide and lactic acid emitted by human skin. For maximum protection against these tiny pests, a concentration of 20% to 50% DEET is typically recommended. Because midges often attack in massive swarms, it is crucial to apply the repellent thoroughly to all exposed skin, as they will quickly find any untreated "gaps." While DEET is effective, some travelers prefer Picaridin or IR3535 as they are less greasy and do not damage plastics or synthetic fabrics like DEET can. Additionally, many locals in midge-heavy areas suggest combining DEET with physical barriers like fine-mesh head nets, as the sheer volume of midges in a swarm can sometimes overwhelm chemical repellents through sheer persistence, even if they aren't technically "biting" the treated areas.