Midge Field Laboratory (02:46)

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The Scottish Highlands are infested with biting insects. Entomologist Dr. James Logan studies what attracts them to humans; he may have found a new repellent. Logan introduces his scientific team.

Midge Study (02:33)

Logan wonders why the insects bite some people, and not others. His team has trouble capturing individual insects for the laboratory; they will conduct experiments in the wild. Volunteers will expose their arms, with a protective barrier and a counting field.

Preparing a Midge Experiment (04:24)

Logan's team sets up a field lab at an Argyle food festival. Logan recruits volunteers while waiting for dusk, when midges come out. It begins raining and they postpone the experiment.

Culicoides Impunctatus (02:47)

Midges can only fly in wind below 5mph, temperatures above eight degrees centigrade, and dry weather. They weigh 1/2000 grams and their wings beat 1,000 times per second. Learn about their anatomy, including saw-like mouths for puncturing skin.

Midge Life Cycle (03:00)

The insects burrow in peaty soil and hatch in early summer; up to 500,000 can hatch in a two square meter area. Forester Henry Dobson suffers bites while monitoring wild boar. Midges are attracted to the carbon dioxide in his breath.

Mechanical Cow Trap (01:22)

Logan uses carbon dioxide and 1-Octen-3-ol, found in cow's breath, to attract midges. The blood sucking flies accompanied mammals to Scotland after the last Ice Age; there are 1,400 species globally.

Successful Midge Field Experiment (03:22)

Rugby club members volunteer for Logan's midge experiment. They wear stockings to protect their arms, and suck individuals into tubes for counting. On average, thirteen land on the test subjects.

Living with Midges (03:26)

An estimated 25% of Scotland is prime territory for the biting insects. Landscape artist John Lowrie Morrison paints indoors to avoid them.

A Midge Meal (04:03)

Female midges only bite to feed a second batch of incubating eggs. Logan uses a powerful microscope to film one feeding on his arm. It pumps saliva into the wound to keep the blood flowing; allergic reactions include swelling and intense itching.

Midge Control Unit (04:06)

Learn about historical figures plagued by the insects. In the 1950s, the British government attempted to control them, including spraying DDT near Edinburgh. Trials failed; they concluded that repellent and mesh hoods are the most effective protection methods.

Midges and Tourism (02:28)

Tourists drawn to Scotland's landscape and wide open spaces are surprised by the biting insects. A campsite manager has seen guests go to the hospital; campfires offer the best protection. Midges are also food for birds and bats.

A Midgey Location (03:41)

Rock climbers brave clouds of biting insects for views. Logan recruits them for his midge experiment. Between 34 and 147 individual insects land on their arms.

Bog Myrtle Experiment (03:18)

Lemon and citronella essential oils are common insect repellent ingredients. At the Royal Botanic Gardens in Edinburgh, Logan makes an anti-midge spray using a citrusy Scottish herb; he finds it ineffective.

Midges and Gender Equality (02:09)

Myths about the biting insects include: they are attracted to red haired people, women, and people with pale skin. Members of a women's shinty team attract a variety of midges.

Natural Midge Repellent (02:40)

In four separate experiments, at least one subject seemed to repel midges. Logan's team collects the sweat of the most repellent person, Cameron, to test for a "magic" chemical in his body odor.

6-Methyl-5-hepten-2-one (03:14)

Human body odor contains hundreds of different chemicals. Logan's team analyzes Cameron's sweat, finding high levels of a chemical known to repel midges. He hopes that it can be developed into commercial repellent.

Credits: The Secret Life of Midges (00:31)

Credits: The Secret Life of Midges