Officer Kennedy from Animal Control assured me he’d never encountered one in this position before. And when I first spotted it, it took me a moment to register what it was. 

But the small, dark shape, wings folded like a tiny umbrella and dark claws touching the water, could only mean one thing: A bat had taken a dip in my toilet. 

It had probably squeezed into the house through a tiny hole left in the course of ongoing renovations. Once inside, it couldn’t find its way back out, and even my spotty housekeeping doesn’t leave enough flying insects to sustain a bat. 

Thirst likely drove it in desperation to one of the few available water sources. Once there, Officer Kennedy explained, it couldn’t leave, since bats can only take flight from a hanging position. Sealed in a plastic jar, the bat was safely carried from the house.

While the position of this stray bat was unusual, it’s not uncommon for bats to take up residence in our homes. A secluded section of an attic with a dime-size exit to the yard is ideal for a small colony. Since bats emerge only at night and head directly outside, the homeowner often remains unaware of their presence. 

Once out, they are key  allies for anyone who enjoys outdoor time on summer evenings; a single bat can eat more than 1,000 mosquitoes an hour. 

How do they  find such quantities of tiny prey in the dark? Contrary to myth, bats are not blind, but they use sound, not sight, for hunting. The mosquito’s annoying hum helps humans find the insect, but bats have a much more sophisticated approach: a form of sonar called echolocation.

The bat calls out and the call bounces off a flying insect, echoing back to the bat. With this information, the bat hones in on the insect’s precise location and swoops in for the kill. And bat sonar reveals not just the location but the insect’s size, shape and direction of motion.

As they patrol the night skies, bats constantly emit high-pitched sounds to find prey. According to Ed Yong’s fascinating book, “An Immense World,” we are fortunate the pitch is too high for human ears to detect since the volume can range anywhere from 110 decibels (think leaf blower) to 138 decibels (think jet engine). Imagine the typical ear-splitting daytime roar of Montclair during leaf blowing season, but lasting all night.

Not all insects are defenseless in the face of bats’ echolocation. Some moth species have sonar-jamming defenses, ranging from scales that absorb rather than echo bat sounds to clicking noises that throw the sonar off. On the other hand, certain flowers seek to lure bats for pollination with leaves that reflect the echoes back to them.

Bat sounds are not just related to hunting. As highly social animals living in dense colonies, bats chatter among themselves in ways that can seem almost human. A study found mother bats speaking to their young (pups) in a kind of baby-talk, helping the pups learn to vocalize. Crowded living quarters can cause social tensions; studies of one bat species revealed that arguments made up 60% of the chatter, typically triggered by such offenses as invasions of personal space or unwanted sexual advances. 

And while we can be thankful our ears don’t detect the sounds of bats hunting, our limited hearing also means we miss out on one of nature’s most enchanting sounds: bat song. Similar to birds, male bats woo their mates with surprisingly sophisticated love songs.

Bats are extremely diverse worldwide, with up to 1,400 different species – about a quarter of all mammal species. 

In our area, only two species are common, unimaginatively named big browns and little browns. (“Big” is a relative term; the biggest big brown bats weigh just under an ounce.) Both species hibernate in winter, preferably in caves or abandoned mines at temperatures in the high thirties. For big brown bats, an accessible, unheated attic sometimes serves the purpose.

Though it is rare, bats can carry rabies, so if you encounter a stray bat or a bat colony in your house call Animal Control rather than attempting removal yourself. As is typical, our bathroom bat tested negative for rabies. 

Bats flying outside at night have no interest in humans and are highly unlikely to pose any risk; the popular image of Dracula-style blood-sucking bats is based on three species found exclusively in Central or South America, not in New Jersey – or Transylvania for that matter.

We have little to fear from bats, but bats, especially the little browns, are in extreme danger from an introduced fatal fungal infection known as white-nose syndrome. Native to Eurasia, where bats are resistant, the fungus was first seen in the U.S. in 2006 in an upstate New York cave. 

It has since spread throughout the East, wiping out entire hibernating colonies and reducing the little brown bat population in our region by 90%. 

There is hope – recent studies suggest some populations have developed resistance – but with a typical female bat giving birth to just one pup a year, any recovery will be slow.

Associated with darkness, caves and nighttime, maligned as bloodsucking vampires, used as cliched background in shlocky horror movies, bats have suffered terrible PR. Even their superhero connection neglects their truly extraordinary superpowers; what if Batman tracked villains using sonar cries and conversed with Robin in frequencies inaudible to other human ears? 

As the only flying mammals, bats seem alien, yet their social life and chatter have near-human qualities. All they want is to be left in peace to hunt down our backyard mosquitoes. Is that so much to ask?

In “What’s in Your Backyard,” Sanford Sorkin and David Wasmuth alternate writing about the birds and beasts you may see around your house. Wasmuth is a local environmentalist and amateur naturalist. He is a Rutgers environmental steward and the founder of the Montclair Backyard Habitat Project. Seen a bird or animal you want to know more about? Write to us at