What will never get an invite to the cookout? Mosquitoes. Yet as we know, those blood-sucking pests love to crash a party. But being the eco-friendly, sustainability-minded Austinites we are, we tend to shy away from chemical-based anything, even when it comes to pest control, opting for all-natural methods, instead. One such technique that may have crossed your radar is the use of our beloved bats to combat (pun intended) the mosquitoes that plague our region every May to September. Question is, will this really work?
A Brief Look Into Our History With Bats
In addition to celebrating weirdness and live music, today’s Austinites love our nocturnal friends. There’s the “Nightwing” bat sculpture, an 18-foot tall public art installation located near the Statesman Bat Observation Center, and the Austin Bat Refuge, which cares for orphaned and injured bats, releasing them back into the wild once they’re ready. We even have an annual Bat Fest, complete with live music, vendors, a bat costume contest, and the chance to catch our famed colony leave for their nightly hunt. It wasn’t always a love affair, though.
While these winged creatures had resided in ATX for decades, their population exploded — to 1.5 million — upon the rebuilding of the Congress Avenue Bridge in 1980, officially making our city home to the largest urban bat colony in the world. The nooks and crannies on the structure’s underside were perfect for nesting, and word among these mammals spread fast; among the people, hysteria did, too.
Austin bats did not originally feel the love they get today. In the 1980s, according to the Austin-based Bat Conservation International, “The public response was near-panic.” Because of long-standing myths about these creatures, such as they’re disease-ridden animals and like to suck on human blood, bats were (erroneously) deemed threats to public health and residents wanted the Austin bats exterminated.
Enter Dr. Merlin Tuttle.
A scientist and bat enthusiast, Tuttle founded Bat Conservation International in 1982, eventually leaving his job as curator of mammals at the Milwaukee Public Museum in Wisconsin in 1986 to run BCI full time. “BCI has been quite successful in educating the public on the benefits of bats in the community,” CultureMap reports. “A few decades after BCI was founded, the bats under the Ann Richards Congress Avenue [Bridge] are thriving as the largest urban bat colony in North America.” And, according to BCI, bat tourism is estimated to bring in $10 million each year.
What Benefits do Bats Provide?
In addition to being pollinators and supporting cave ecosystems, bats also dine on insects. In fact, the National Park Service says that bats eat so many insects across the country each night, it adds up to $3.7 billion worth of yearly pest control. This means farmers don’t have to spend as much money on pesticides to protect their crops and other residents won’t break the bank ridding their homes and businesses of such unwanted invaders.
With information like this, it stands to reason that bats would indeed make the safest, most efficient way of eliminating the mosquito population. There’s been a surge in production of bat houses over the years for this very purpose, and even BCI advocates for their use in controlling insects overall. Perhaps the strongest driver of the belief that bats can eradicate mosquitoes comes from a 1950s study in which a group of bats were placed overnight into a chamber filled with 2,000 mosquitos. “In the morning, the mosquito population had fallen to roughly 200-300,” the report states, adding in a subsequent chart that the bats ate nearly 10 mosquitoes per minute.
Do Bats Really Work as Mosquito Controllers?
What the study failed to note, is that out in the wild, a bat’s environment isn’t so micromanaged. They’re free to gorge on their preferred foods. Our Mexican free-tailed bats, for example, readily indulge on flying insects, such as earworm moths and flying ants and beetles. Mosquitoes don’t show up on the menu as often. “Bats are very poor predators of mosquitoes,” Joe Conlon, a medical entomologist with the American Mosquito Control Association, told WebMD in 2016. “Less than 1% of their foodstuffs are mosquitoes. They would starve if they relied on mosquitoes.”
Real-world case studies back this up, as well. Take the famed 30-foot bat tower in Sugarloaf Key, Fla., for instance. It was built in 1929 in hopes of diminishing the area’s mosquito population. It didn’t work. Not one bat ever made its home there, despite several attempts at coaxing. Independent from an early age, bats are more inclined to seek out their own shelter — like inside the hollows of a dead tree — rather than a meticulously constructed, human-built refuge.
Natural Options That Are Actually Effective
Of course, you can always purchase and install a bat house for funsies. Who knows? A few may come to roost and snack on the moths and flying ants and beetles that may congregate around your property. For environmentally friendly methods of eradicating mosquitoes, though, try these tips from the American Mosquito Control Association and the CDC:
- Remove all standing water from your property, as that can provide mosquitoes a place to lay their larvae, thus increasing their population.
- Install “bug lights” in your outdoor fixtures. They do not repel mosquitoes, but unlike incandescent bulbs, bug lights do not attract them, either.
- Use citronella candles outside, as the vapor emitted can repel mosquitoes.
- Consider integrated mosquito management, which, instead of endorsing the spraying of pesticides everywhere, focuses on following the mosquito life cycle to eliminate eggs, nests, and adults already in existence.