Like most animals, the hippopotamus becomes aggressive when it hears a stranger approaching. AIR MAIL Pilot has uncovered another, more peculiar response. To put it nicely, hippos poop upon hearing an unknown voice. To be more precise, they run towards the unfamiliar hippo, point their behinds at it, and spin their tails while defecating.

Like many species, hippos are vulnerable to extinction, and scientists are working hard to protect them. To keep hippopotamus populations at sustainable levels, conservationists often move the animals, which live in Sub-Saharan Africa, to new locations. Hippos are social and usually travel in packs. But conservationists found that they can become quite hostile towards animals outside of their friend group.

It’s easier for conservationists to deal with hippos, which can weigh up to 4,000 pounds, if they’re in a good mood. So, a group of researchers from the University of Saint-Étienne studied a group of hippopotamuses on a nature reserve in Mozambique to understand how the animals acclimate to new environments. They hid speakers around the reserve and played recorded hippo sounds—which they call “wheeze-honks”—made from both creatures the group did and didn’t know.

When the wheeze-honks of friends and neighbors played, the hippos didn’t react. But sounds from unknown hippos provoked an extreme response. Immediately, and without warning, the hippos charged towards the noise and pooped while vigorously spinning their tails to spray the dung as far as possible. Although no one enjoys an interruption from a stranger, this was a rather extreme response.

As unpleasant as this sounds, it signals good news. According to Nicolas Mathevon, the lead researcher on the study, these findings will help conservationists move hippos in a way that makes both animals and humans happy. “Before relocating a group of hippos to a new location, one precaution might be to broadcast their voices from a loudspeaker to the groups already present,” he told The Times of London. “They become accustomed to them and their aggression gradually decreases.”

In other words, hopefully they’ll spray a little less poop next time. —Elena Clavarino

Mmmm, sausage. It’s a type of food that’s been around since at least ancient Greece; we know this because Homer mentions sausages in The Odyssey, written around 700 B.C.E. (The epic poem’s hero, Odysseus, is described during a sleepless night as tossing about like a sausage being turned over a fire.) Drones, meanwhile, are a more recent invention. But just last month, the unlikely team of sausages and drones saved a dog from drowning. Human ingenuity played a role as well.

The drama began when Millie—a Jack Russell terrier-whippet mix—slipped out of her leash while on a walk near her home in Havant, a small coastal town in Hampshire, England. Millie ran off, and was eventually discovered on some local mudflats. With the tide rising. Millie was in danger of drowning, but she managed to avoid the cops, firefighters, and others who tried to rescue her while navigating the unreliable terrain.

The situation was getting desperate. That’s when one of the rescuers had an idea: what if they dangled sausages from a drone, as bait to lure Millie to higher, safer ground?

“It was a crazy idea,” Chris Taylor, the head of a local drone-based search-and-rescue team, told The Guardian. Before taking action to find out whether it just might work or not, the rescuers—sticklers, apparently—checked to make sure that a sausage-laden drone flight wouldn’t somehow run afoul of Civil Aviation Authority regulations. Then, dutifully consulting their drone’s maximum takeoff weight, they realized they could only attach a single sausage, rather than a more alluring string of five or six. But what if a single sausage wasn’t fragrant enough to tempt Millie? The margin for error was slim.

Frying against time, an unidentified local woman quickly cooked an unidentified local sausage, which was then attached by a string to a drone. It worked: Millie either caught the scent or was simply intrigued by the sight of a sausage hovering in mid-air as if by magic—Air Mail Pilot would be intrigued, too—and was led to higher ground, where she was reunited with her owner, Emma Oakes, a care manager.

“Millie really likes food and she’ll eat anything you give her … raw carrots, cucumber, but she much prefers sausages,” Oakes told The Guardian. “So dangling a sausage was probably the best thing they could lure her with.”

“We certainly would consider using sausages again,” Taylor, the search and rescue leader, added, while pointing out that every operation presents unique challenges. Air Mail Pilot would like to offer this suggestion: try a salmon steak next time a cat is stuck in a tree. —Bruce Handy

There are two things that bring people together on the Internet: photos of cute dogs and wholesome humor. Matt Nelson is dedicated to both. Between his two Twitter accounts—WeRateDogs and Thoughts of Dog—Matt has built an online community of over 12 million people.

Matt, 24, grew up in northern Virginia with golden retrievers—Holly, Daisy, Sizzle, and Zoey. “Dogs have this calming essence that was really helpful in my formative years,” he tells AIR MAIL Pilot.”I’ve always loved dogs, and I was delighted to learn that so do most other people, and the entirety of the internet.”

He started his first Twitter account, WeRateDogs, in 2015, while studying golf management at Campbell University in North Carolina. He used the account to share photos his followers submitted, and to rate the pictured pups on a scale from 1 to 10. Within the first week, he had over 10,000 followers. Within a month, he had over 100,000. Today, the account has 9.1 million followers. The latest post is of a pug named Apple. She earned a modest 12 out of 10 rating.

“We were immediately overwhelmed with DMs and requests to post dogs … it had a sense of community and a sense of purpose” Matt says.

In 2017, he created a spin-off Twitter account, Thoughts of Dog. On it, Matt mimics dogs’ daily reflections, attempting to capture the excitement of going on a walk or the joy of getting a treat. His childhood dog Zoey, who is now starting to grow gray hairs, often inspires these posts.

Like his first account, the following grew exponentially. At one point, it even surpassed the popularity of its big brother, WeRateDogs. “People love to get lost in a world where a dog is talking to them,” he says. “It really does [walk] the line between profound and cheesy.”

Matt has used this online success to help dogs offline. In 2016, a fan of WeRateDogs—a man whose pugs and yellow Labrador Retriever were frequently featured on the Twitter—asked Matt to help him raise money for his elderly pug who required an expensive wheelchair. In less than an hour, the GoFundMe raised more than the owner needed.

Starting in 2017, Matt posted fundraisers on the accounts every Friday. One GoFundMe to raise money for a dog’s brain surgery received $20,000 in one day. “The sky was the limit as to how much our audience could raise” Matt said.

All of this lead Matt to create the 15/10 Foundation, a nonprofit that sponsors dogs with medical issues. “We’re trying to make them just as adoptable as the dog besides them,” he says.

Don’t worry, Matt is still posting cute photos and anecdotes online. “Now, it’s more about how many people can I make smile with a post.” —Jacob Robbins