It only takes one wrong step near a lake in the winter for disaster to happen. Pepper, the dog and his mom found that out the hard way.

The two of them were taking a morning walk in Chicago along Lake Michigan when Pepper, a 7-year-old dog, got free of its rope, slipped on some rocks, and fell onto the ice sheets of the lake. As Pepper tried to climb back up to his human owner, the ice around him broke, and he began floating (漂浮) away!

Since the water was so cold, Pepper should be saved as soon as possible. As Fire Deputy District Chief Jason Lach said, hypothermia (a serious medical condition caused by very low temperature) can start within several minutes. Thankfully, firefighters were already nearby practicing underwater ice dives.

Just 10 minutes later, 40 rescue (救援) workers arrived, along with fire department vehicles and a helicopter. By the time the officials in the helicopter noticed Pepper, he and his ice float were 500 feet out into the lake. Firefighter Chris Iverson dove into the water and swam out to Pepper. Chris calmed the dog down and tied him to a safety sling (吊索). Meanwhile, firefighter Emerson Branch swam out with a rapid deployment craft, which he and Chris used to bring Pepper safely to shore. The rescue only took about 15 minutes. When the firefighters reached dry land with Pepper, they dried him using a towel and played the pass-the-dog to get him back to his human owner.

Caretakers at Veterinary Emergency Group Hospital made sure Pepper was OK. But Jason hopes his rescue will be a lesson for others. “The dog was good, warmed up to its owner, and went on its happy way,” Jason said. “But stay off the ice. It’s never safe, …Step into a hole, and you’re out of sight.”

You may have recently seen a video from the Beijing Wildlife Zoo going viral(走红). What exactly was so interesting about this video? It shows a dog playing with big cats four to five times its size! Many people might wonder if this dog has a death wish, but it seems that the dog and the big cats are good friends.

The dog was actually raised alongside the lion and tiger cubs(幼兽), making up a strange but loving family, according to zoo officials. If you think this is a bit too wild, just remember that cross-species friendship has been common for centuries. People have domesticated(驯养) many animals, especially cats and dogs, and formed bonds with them as pets. Perhaps you even have a pet yourself.

There are many other examples of cross-species friendships in captivity(圈养). At an animal sanctuary(庇护所) in Santiago Chile, a kitten named Marina and a piglet named Laura formed a friendship after they both came to the park. As neither animal had a mother sanctuary staff said they immediately bonded when they met. Laura had been rescued from a slaughterhouse(屠宰场) while Marina had been rescued from the street.

One possible explanation for these friendships is the environment of the zoo. Animals don’t hunt for their food and don’t need to worry about marking their territory(领地) or looking for mates in the way an animal in the wild would. “All those activities take time and energy, and if these needs are removed, the animals get bored,” Gordon Burghardt, a psychologist at the University of Tenessee, US, told The Atlantic magazine.“ In this particular situation, the animal’s motivation to engage socially and playfully may be higher in its need level than eating.”

Marc Bekoff, former biology professor at the University of Colorado, US, told Slate magazine, “I think the choices animals make in cross-species relationships are the same as they do in same-species relationships. Some dogs don’t like every other dog. Animals are very selective(严格筛选的) about the other individuals who they let into their lives.”

Everybody hates rats (big mice). But in the earthquake capitals of the world — Japan, Los Angeles and Turkey — rats will soon be man’s best friends.

What happens after an earthquake？We send in rescue dogs. Why？Because they can smell people. Dogs save lives. They help rescuers to find living people. But dogs are big and they can’t get into small spaces. So now a new research project is using a smaller animal to save lives: the rat.

How does it work？First, the rat is trained to smell people. When this happens, the rat’s brain gives a signal (信号). This is sent to a small radio on its back, and then the rescuers follow the radio signal. When the rat’s brain activity jumps, the rescuers know that someone is alive. The rat has smelled that person.

Although there are already robots which can do this job, rats are better. Christian Linster at Cornell University, New York, says, “Robots’ noses don’t work well when there are other smells around. Rats are good at that.” Rats can also see in the dark. They are cheaper and quicker to train than dogs, and unlike robots, they don’t need electricity!

The “rat project” is not finished, but Julie Ryan of International Rescue Organization in Scotland says, “It would be wonderful. A rat can get into spaces we can’t get to, and a rat will get out if it isn’t safe.” Perhaps for the first time in history, people will be happy to see a rat in a building (but only after an earthquake, of course).