Poop-Eating Naked Mole Rats Get Suckered Into Babysitting

The animal kingdom is filled with deadbeat dads. Raising kids takes energy, and nature often rewards the father who walks (or hops or swims or flies) away. Fewer and farther between are the animal moms who just can’t be bothered. Most of them leave their young to fend for themselves, but there are some who get other animals to do the child-rearing for them.

Naked mole rat mothers definitely fall into that category. Dominant rats bear pups, then leave the rest to their subordinates. Why would the subordinates agree to this plan? Two Japanese researchers have a theory: Pregnancy hormones in the mother’s poop trick the other rats into feeling maternal.

Like ants and bees, naked mole rats follow a eusocial colony structure. That means that there’s one queen rat, a few virile males, and a whole bunch of female workers. The queen’s job is to make babies; the male rats help make babies; and the worker rats do absolutely everything else. This includes digging tunnels, keeping the chambers clean, and defending the colony. It also means raising a whole lot of rat babies. 

There’s something else you should know about naked mole rats: they eat poop. The rats’ favorite foods are roots and plant bulbs, which can be pretty hard to digest—so the rats chow down twice. They eat, pass their meal, then eat it again. But they don’t just eat their own poop. The rats use specialized bathroom chambers, which means that their recycled food could have come from anyone—including the queen.

Worker rats don’t have mature sex organs of their own, which means they don’t make sex hormones. But when the queen is knocked up, her poop is positively packed with estrogen. As reported this week in Nature News, researchers from Japan's Azabu University recently presented research findings at the Society for Neuroscience meeting in Chicago that suggest the queen’s hormones inspire maternal impulses in her subordinates. 

First, the scientists played a recording of crying rat pups for a group of subordinate female rats. The worker rats whose queen had just given birth were very interested in the pups’ cries. The other workers were not.

The next step was finding out how the queen rat’s poop affected her workers. The researchers gave subordinate rats hormones from their pregnant queen’s feces. Sure enough, the worker rats’ estrogen levels increased, as did their interest in the sound of crying rat babies. 

NOTE: Naked mole rats are not moles, or rats, or even naked, but that’s a story for another day.

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Big Questions
Why Do Cats Freak Out After Pooping?
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Cats often exhibit some very peculiar behavior, from getting into deadly combat situations with their own tail to pouncing on unsuspecting humans. Among their most curious habits: running from their litter box like a greyhound after moving their bowels. Are they running from their own fecal matter? Has waste elimination prompted a sense of euphoria?

Experts—if anyone is said to qualify as an expert in post-poop moods—aren’t exactly sure, but they’ve presented a number of entertaining theories. From a biological standpoint, some animal behaviorists suspect that a cat bolting after a deposit might stem from fears that a predator could track them based on the smell of their waste. But researchers are quick to note that they haven’t observed cats run from their BMs in the wild.

Biology also has a little bit to do with another theory, which postulates that cats used to getting their rear ends licked by their mother after defecating as kittens are showing off their independence by sprinting away, their butts having taken on self-cleaning properties in adulthood.

Not convinced? You might find another idea more plausible: Both humans and cats have a vagus nerve running from their brain stem. In both species, the nerve can be stimulated by defecation, leading to a pleasurable sensation and what some have labeled “poo-phoria,” or post-poop elation. In running, the cat may simply be working off excess energy brought on by stimulation of the nerve.

Less interesting is the notion that notoriously hygienic cats may simply want to shake off excess litter or fecal matter by running a 100-meter dash, or that a digestive problem has led to some discomfort they’re attempting to flee from. The fact is, so little research has been done in the field of pooping cat mania that there’s no universally accepted answer. Like so much of what makes cats tick, a definitive motivation will have to remain a mystery.

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Watch a School of Humpback Whales 'Fish' Using Nets Made of Bubbles 

Just like humans, humpback whales catch many fish at once by using nets—but instead of being woven from fibers, their nets are made of bubbles.

Unique to humpbacks, the behavior known as bubble-net feeding was recently captured in a dramatic drone video that was created by GoPro and spotted by Smithsonian. The footage features a school of whales swimming off Maskelyne Island in British Columbia, Canada, in pursuit of food. The whales dive down, and a large circle of bubbles forms on the water's surface. Then, the marine mammals burst into the air, like circus animals jumping through a ring, and appear to swallow their meal.

The video offers a phenomenal aerial view of the feeding whales, but it only captures part of the underwater ritual. It begins with the group's leader, who locates schools of fish and krill and homes in on them. Then, it spirals to the water's surface while expelling air from its blowhole. This action creates the bubble ring, which works like a net to contain the prey.

Another whale emits a loud "trumpeting feeding call," which may stun and frighten the fish into forming tighter schools. Then, the rest of the whales herd the fish upwards and burst forth from the water, their mouths open wide to receive the fruits of their labor.

Watch the intricate—and beautiful—feeding process below:


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