Do bats and purple martins eat mosquitoes?
Quick answer
Not meaningfully. Bats and purple martins eat insects, but mosquitoes make up under 1% of their diet — they prefer larger, higher-calorie prey like moths and beetles. Purple martins actually eat dragonflies, which are far more effective mosquito hunters, so a backyard bat house or martin gourd won’t noticeably cut your bites.
Why it doesn't work
Bats and purple martins are voracious insectivores, which makes the story intuitive — and wrong at the scale of a backyard. The problem is dietary preference and energetics. A mosquito is a tiny, low-calorie prey item. Insectivorous bats and aerial-foraging birds preferentially take larger, more profitable prey — moths, beetles, flying ants, midges, and, crucially, larger flies and dragonflies — because chasing thousands of mosquitoes is a poor energy return.
Dietary studies bear this out. Analyses of insectivorous bat diets (and the classic controlled work on whether bats meaningfully suppress Culex near oviposition sites) find mosquitoes are a small single-digit-or-less percentage of intake; bats do not reduce mosquito biting pressure in a yard. The "a bat eats 1,000 mosquitoes an hour" figure traces to a 1960 lab demonstration in which starved bats were released into a room full of only mosquitoes — an artificial ceiling rate, not a field diet.
Purple martins are the more counterproductive case. Martins are daytime, high-altitude aerial foragers; mosquitoes are mostly low-flying and crepuscular/nocturnal, so the overlap is small. The Purple Martin Conservation Association itself debunks the mosquito-control claim. Worse, a martin’s preferred prey includes dragonflies — among the most effective natural mosquito predators, as both aquatic nymphs and adults. Encouraging martins can mean removing more mosquito predators than mosquitoes.
None of this is a reason to discourage bats or martins — both are ecologically valuable and worth supporting for their own sake. It is only a reason not to install them as a mosquito-control device. They will not measurably lower the host-seeking female population around your patio. If that’s the goal, you need a method that specifically targets host-seeking females, which broad-diet predators do not.
References
- Reiskind, M.H. & Wund, M.A. (2009), "Experimental assessment of the impacts of northern long-eared bats on ovipositing Culex (Diptera: Culicidae) mosquitoes," Journal of Medical Entomology 46(5):1037–1044.
- Gonsalves, L. et al. (2013), bat-diet analyses showing low mosquito proportion.link pending verification
- Purple Martin Conservation Association, "Purple Martins and Mosquitoes."link pending verification
What to do instead
The honest answer isn't "give up" — it's to target the host-seeking females directly. A CO₂ + heat trap broadcasts the breath-and-body cues mosquitoes actually follow, drawing them away from you and capturing them, without spraying pesticide across your yard.
See the SkeeterSwitch bundleCommon questions
Do bats eat enough mosquitoes to control them?
No. Mosquitoes are a tiny fraction of a bat’s diet; bats prefer larger, higher-calorie prey, and field studies show no meaningful mosquito reduction.
Where did "bats eat 1,000 mosquitoes an hour" come from?
A 1960 lab test with starved bats in a room containing only mosquitoes — an artificial maximum, not a real-world diet.
Do purple martins eat mosquitoes?
Very few. They forage high and by day, missing low, dusk-active mosquitoes, and they eat dragonflies, which are major mosquito predators.
Should I take down my bat or martin house?
No — both are great for wildlife. Just don't rely on them to reduce mosquito bites.