Female botflies catch mosquitoes in mid-air and glue eggs to their underside — turning the mosquito into an unwitting delivery courier. The strategy is called phoresy.
JournalJournal of Medical EntomologyShare →
Human Botfly
Dermatobia hominis
Doesn't bite you. Hires the mosquito to deliver its eggs. Hatches under your skin.
Curated and rated by Sheriff Six-Legs and The Wild Pest field team · Six Legs Score™ (87/100, Outlaw tier) · Published Apr 25, 2026 · Updated Apr 28, 2026 · Released CC BY 4.0
87Six Legs
Six Legs Score™
87 / 100
The human botfly delivers its eggs to humans by hijacking other biting insects — a parasitic strategy called phoresy. The larvae develop under human skin, breathe through a small pore, and emerge weeks later. Few biological strategies on Earth combine this much wildness, weirdness, and visceral human impact.
Size
Adult fly 12–18 mm
Lifespan
Adult: 1–2 weeks; larva: 6–8 weeks under host skin
Range
Mexico to northern Argentina
Diet
Larva: host tissue fluids. Adult: nothing.
Found in
Lowland tropics, especially humid forest edge
On the Range
Field guide
Dermatobia hominis is a fly native to Central and South America. The adult fly does not bite humans — it cannot. Instead, the female employs a remarkable strategy called phoresy: she captures a blood-feeding insect (typically a mosquito), glues 15–30 eggs to its underside, and releases it. When the mosquito later lands on a warm-blooded host, the host's body heat triggers the eggs to hatch. The larvae drop onto skin, burrow in, and develop in a small subcutaneous chamber for six to eight weeks. The larva keeps a tiny breathing pore open at the skin surface and does not migrate through the body. Eventually the mature larva emerges on its own, drops to the ground, and pupates in soil. Botfly infestations in humans are not life-threatening but are notoriously memorable. The species is studied seriously by parasitologists and feared casually by everyone who has ever traveled to the rainforest.
7 wild facts on file
Botfly eggs hatch when they sense the warmth of a host's skin — meaning the eggs only release when the moment is right.
A developing botfly larva keeps a tiny breathing pore open at the skin surface — block it, and the larva will eventually leave.
JournalJournal of Travel MedicineShare →
A botfly larva develops under the skin for six to eight weeks before emerging — and adult bots themselves live only a week or two.
Adult human botflies cannot bite. They have no functional biting mouthparts at all.
Female botflies have been documented hijacking at least 40 different species of biting insects — not just mosquitoes.
JournalJournal of Medical EntomologyShare →
Despite the unsettling lifecycle, botfly larvae don't transmit disease. The infection is confined to one small site under the skin.
AgencyCenters for Disease ControlShare →
Cultural file
Botflies feature prominently in travel-medicine literature and remain a top recurring subject of doctors-without-borders case reports. Folk-medicine removal techniques across Central America include taping bacon, raw meat, or a thick slurry of petroleum jelly over the breathing pore — practices that, surprisingly, do work. The fly's hijacking strategy is now studied as a potential model for biopharmaceutical drug delivery.
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