Many people are terrified of bats. However, a creature that is far more frightening is the mosquito.
It is the deadliest creature in the world because it can transmit potentially lethal diseases like yellow fever, West Nile virus, and malaria.
Bats love to eat these little serial killers, but will also eat many other kinds of bugs. Just how many mosquitoes a bat eats per night is a subject of debate.
How Many Mosquitoes Do Bats Eat?
One study in 1960 suggested that bats could eat 1,000 mosquitoes an hour, but this study’s findings have been questioned. Small bat species like the little brown bat eat mosquitoes more often than larger bats. It has been estimated that bats eat at least one-third of their weight in insects a night, which comes to 500 to 3,000 bugs a night.
Smaller Bats Eat More Mosquitoes
Of the forty species of bats in North America, only four do not eat insects. Most survive by eating bugs. They eat all kinds of bugs, not just mosquitoes.
Larger bats will eat mosquitoes, but they do not prefer them as they aren’t very filling. Analysis of their feces, called guano, shows that mosquitoes make up very little of their diets.
It’s the smaller bats that have a larger bulk of mosquitoes in their diet. The little brown bat, which is the most common North American bat in North America, includes mosquitoes on their nightly menu.
A 2018 University of Wisconsin-Madison studyshowed that little brown bats ate many species of mosquitoes. Mosquito DNA was found in the guano of all little brown bat guano samples.
In contrast, mosquito DNA was found in less than half of another common species in North America, the large brown bat (clearly, someone was not creative in naming these species.)
Any insect takes a lot of energy to hunt down. Mosquitoes do not provide much in the way of calories. Larger bats prefer larger prey, like beetles, moths, and caddisflies.
The Whole “Bats Eat 1,000 Mosquitoes an Hour” Thing
There are many websites on the Internet claiming that bats eat up to 1,000 mosquitoes an hour. This claim is based on a 1960 study of bats in laboratories.
Mosquitoes and fruit flies were released and the bats were timed as to how many mosquitoes they ate. Bats ate about ten insects in “several minutes”.
One bat even caught two fruit flies in half a second. Other bats ate ten mosquitoes a second.
The study, unfortunately, started coming to some remarkable conclusions that if a bat ate ten mosquitoes a second, then they could eat 1,000 a night.
Bats in laboratories do not need to fly miles and miles searching for, chasing, and capturing food. Hunting takes a considerable amount of a bat’s time.
Also, bats do not spend all night stuffing their faces with bugs, mosquitoes, or otherwise. They also have other bat-things to do, like cleaning, socializing, drinking, and flying about.
Just because a person can down ten M&Ms a second does not mean they will spend all night doing nothing but eating 1,000 M&Ms an hour. Not most people, anyway.
Basically, Bats Eat a Lot of Bugs
Although the exact number of how many bugs a bat eats per night is unknown, it is known that they eat a lot of bugs. Just how much is a lot?
Consider that a little brown bat weighs 0.29 ounces. According to the United States Geological Survey (which looks at science in general), one bat eats four to eight grams or 0.14 to 0.28 ounces of bugs a night.
This has been estimated to be about 500 bugs a night.
The USDA looked at one cave of a colony of gray bats, in particular in Sylamore District Cave. Gray bats, which are sadly endangered, weigh about ten grams or 0.35 ounces.
They estimated that each bat ate at least one-third of its body weight a night. This means a single gray bat eats about 3,000 insects a night.
This would add up to 150 billion insects for the months they are active in a year. It is unknown how much of that diet is made up of mosquitoes.
The largest colony of bats in America involves 20 million Mexican free-tailed bats found in Texas’ Bracken Cave.
The USDA estimates that if every bat in the colony is able to have a good night hunting, the colony eats a staggering 220 tons of insects each night. That’s about 3,000 insects per bat each night.
Again, it is not known how many of those insects are mosquitoes.
Bats Helping in Mosquito Control
One of the selling points to putting bat houses in a yard is that the bats reduce mosquitoes. Actually, the accuracy of this claim is debatable, since mosquitoes do not make up a huge portion of a bat’s diet.
However, a Michigan study from 2009 noted that bats slowed down how often mosquitoes reproduced. This is thought to be because blood-filled female mosquitoes are easier for bats to catch.
Researchers set up two enclosures – one without bats and one with bats. The study then shows that the cage with bats had about 32 percent lesser mosquitoes than the one that doesn’t have.
Bats are important in other ways, not just for eating bugs. For example, bats are extremely important for the pollination of over 530 plant species, like the saguaro cactus and the tequila plant.
Frequently Asked Questions About How Many Mosquitoes Bats Eat
How Many Bugs Do Bats Eat?
According to the USDA and Bat Conservation International, one small bat can eat about 500 insects a night. In fact, it’s estimated that one Mexican free-tailed bat colony in Texas can eat 22o tons of insects every night.
What Do Bats Eat?
Not all bats eat insects, although the majority of species around the world do. Other species eat mice, frogs, lizards, fish, fruit, pollen, and nectar. But, unlike others, the vampire bat survives by blood.
If I Buy a Bat House, can it Help Get Rid of the Mosquitoes in My Yard?
It has been estimated that mosquitoes make up less than one percent of many insect-eating bat species. Relying on bats to control any insect pest in your home or yard is unreliable. Also, it can take years before any bat chooses to roost in a bat house.
The Least You Need to Know
Bats eat at least one-third of their body weight every night in bugs, including mosquitoes. This means they can eat from 500 to 3000 insects a night.
There aren’t any species of bats that just eat mosquitoes. They eat a wide variety of bugs.
Smaller bats have mosquitoes on their menus more often than larger bats.