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Newcastle University
Newcastle University

Scientists Create Tiny 3D Glasses for Mantises

Newcastle University
Newcastle University

If the female African mantis (Sphodromantis lineola) pictured above wearing teensy 3D glasses looks like she’s on her way to the movies, that’s because she is. But it wasn’t just insect dress-up time in the laboratory. The minuscule specs and movie theater were an experiment to find out if mantises can see in three dimensions.

The idea of not being able to see 3D sounds pretty weird, but scientists say stereoscopic, or 3D, vision is actually pretty rare in the animal kingdom. Humans have it (most humans, anyway), as do other primates, horses, birds, cats, and toads. However, it’s generally believed that invertebrates like bugs see the world in only two dimensions. To date, only one invertebrate has been shown to possess stereoscopic vision: the praying mantis. 

The original mantis vision experiment occurred in the 1980s. At the time, the researcher was pretty limited in the 3D images he could create. More than 20 years later, 3D technology is everywhere, and a team of researchers figured they could build a pretty decent mantis movie theater. For science.

Scientists Vivek Nityananda, Ghaith Tarawneh, Ronny Rosner, Judith Nicolas, Stuart Crichton, and Jenny Read outlined their methods and findings in a paper published yesterday in Scientific Reports. The first step was to make a movie that would interest a mantis audience. They opted for an animation of a spiraling disc against a brightly colored background. The disc bounced around the screen, occasionally hovering in place—a bug-like movement pattern that has been shown to keep the mantises’ attention and even provoked them to strike. They set the animation to play on a high-resolution computer monitor and constructed a small black tunnel to limit the size of the screen. 

Next, they cut out little circles from blue and green plastic filters. They stuck the mantises briefly in a freezer to sedate them, then pulled them out and affixed the 3D glasses to their faces with beeswax and rosin. Looking like extras in a B-52s video, the mantises then went back to their cages to recover from the weirdness they’d just experienced.

 

Image credit: Newcastle University

The next day, the researchers took out the newly bespectacled bugs and brought them to the little movie theater. They set them in front of the tunnel and recorded how many times the mantises tried to strike the images they saw on the screen.

The results confirm the mantises’ use of 3D vision. When the target was rendered in three dimensions and seemed to pop off the screen, the mantises lunged for it. When it was 2D, they didn’t show much interest.

The research team was pleased with their results. "Despite their minute brains, mantises are sophisticated visual hunters which can capture prey with terrifying efficiency,” lead researcher Jenny Reed said in a press statement. “We can learn a lot by studying how they perceive the world.” 

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holidays
Bleat Along to Classic Holiday Tunes With This Goat Christmas Album
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Feeling a little Grinchy this month? The Sweden branch of ActionAid, an international charity dedicated to fighting global poverty, wants to goat—errr ... goad—you into the Christmas spirit with their animal-focused holiday album: All I Want for Christmas is a Goat.

Fittingly, it features the shriek-filled vocal stylings of a group of festive farm animals bleating out classics like “Jingle Bells,” “Rudolph the Red-Nosed Reindeer,” and “O Come All Ye Faithful.” The recording may sound like a silly novelty release, but there's a serious cause behind it: It’s intended to remind listeners how the animals benefit impoverished communities. Goats can live in arid nations that are too dry for farming, and they provide their owners with milk and wool. In fact, the only thing they can't seem to do is, well, sing. 

You can purchase All I Want for Christmas is a Goat on iTunes and Spotify, or listen to a few songs from its eight-track selection below.

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Animals
If You Want Your Cat to Poop Out More Hairballs, Try Feeding It Beets
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Have you ever wondered if there’s a way to get your cat to poop out its hairballs instead of hacking them up? If so, you’re likely a seasoned cat owner whose tolerance for gross stuff has reached the point of no return. Luckily, there may be an easy way to get your cat to dispose of hairballs in the litter box instead of on your carpet, according to one study.

The paper, published in the Journal of Physiology and Animal Nutrition, followed the diets of 18 mixed-breed short-haired cats over a month. Some cats were fed straight kibble, while others were given helpings of beet pulp along with their regular meals. The researchers suspected that beets, a good source of fiber, would help move any ingested hair through the cats’ digestive systems, thus preventing it from coming back up the way it went in. Following the experiment, they found that the cats with the beet diet did indeed poop more.

The scientists didn’t measure how many hairballs the cats were coughing up during this period, so it's possible that pooping out more of them didn’t stop cats from puking them up at the same rate. But considering hairballs are a matter of digestive health, more regular bowel movements likely reduced the chance that cats would barf them up. The cat body is equipped to process large amounts of hair: According to experts, healthy cats should only be hacking hairballs once or twice a year.

If you find them around your home more frequently than that, it's a good idea to up your cat's fiber intake. Raw beet pulp is just one way to introduce fiber into your pet's diet; certain supplements for cats work just as well and actually contain beet pulp as a fiber source. Stephanie Liff, a veterinarian at Pure Paws Veterinary Care in New York, recommends psyllium powder to her patients. Another option for dealing with hairballs is the vegetable-oil based digestive lubricant Laxatone: According to Dr. Liff, this can "help to move hairballs in the correct direction."

[h/t Discover]

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