This Week in Science: The loudest bat gets the worm and surprising reproductive abilities of naked mole rats

Pulse contributor Bethany Brookshire shares the latest findings on bat calls and milk production among naked mole rats.   

New research on ultrasonic bat calls is providing clues on how bats call dibs for their food around dinner time.

Dr. Bethany Brookshire, a science writer and regular Pulse contributor, says that conversation boils down to something very simple:

“Stand back, that bug is mine.”

The social calls are being recognized among big brown bats, specifically male big brown bats, which are ubiquitous across North America. 

“People would go out and record bats at night and they recognized at least six different types of calls, but had no idea what they were for and couldn’t trace them to a particular bat,” says Brookshire. 

So researchers decided to test the bats in captivity. The bats were taken to a large room, where they flew in pairs above a meal worm trapped on the floor. Soon enough, the bats started making social calls consisting of three or four chirps and a long buzz noise. 

“They found that the loudest and most frequent caller got the meal worm in the end,” she says. 

These high-pitched sounds are inaudible to humans but were altered in a video to be brought down to the range of human hearing.

“Since we’re now able to show that a particular social call means something, [researchers] might be able to pinpoint what other social calls mean and also do things like playback studies in which social call recordings are played out in the wild to see if they change the behavior of other bats in the wild.” 

High reproductive output of naked mole rats

In other quirky science news, researchers recently discovered that naked mole rats produce an astonishing 50 percent of their body weight in milk per day while they nurse their litter of up to 12 pups. 

Naked mole rats are eusocial, which means they operate like bees.  They have a queen, a few males used for breeding and a large force of female workers to help care for the young and keep the queen fed.  The queen does all of the breeding in the colony. Researchers recently set out to find out how these queens produce their milk and whether or not the milk was rich in fats and protein. 

“It turns out naked mole rats produce pretty average milk – not any fattier or proteinaceous than other rodent milk,” Brookshire says. “And to support these massive litters, they produce half their body weight in milk every day while they nurse.” 

A huge number when you consider queen mole rats breed twice a year for about 30 years. 

Brookshire is a science writer and educator for Science News and Society for Science and the Public, and writes for Eureka lab. She blogs under the name “Scicurious” and has a knack for finding the strangest science experiments and studies under the sun.