Many children are introduced to animals through TV shows or movies. Shaun the Sheep, an animated (动画) series, features a variety of animals living at the Mossy Bottom Farm. Among them, naughty Shaun is the clever leader of his group of sheep. Sheep in this animation look a bit different from common ones because the TV show used the Valais Blacknose sheep as the model.

There are few animals that make people say “Aww!” in a high voice as quickly as the Valais Blacknose sheep. Known as the cutest sheep in the world, these animals come from the Valais region in Switzerland. They are instantly recognizable thanks to their striking appearance. They have soft, white wool, which contrasts with the black small pieces spread evenly over their faces and found on their ears, knees, and ankles (脚踝). The sheep also have horns (角) popping out of their wool.

The Valais Blacknose sheep have a rich history deeply rooted in the Swiss Alps. They were originally raised in the 15th century for their highly valued wool, which has been traditionally used to produce luxurious textiles and garments (奢华的纺织品与服装). However, it was not until 1962 that they were officially recognized as a species. Their population once decreased, but dedicated conservation efforts have been implemented to protect this unique species. These efforts have been successful, and the Valais Blacknose sheep can now be found in various parts of the globe.

Looking like a combination of a lamb and a teddy bear, the Valais Blacknose sheep has found its place in the hearts of many people. They are also raised as pets due to their cute, gentle, and friendly nature, which makes them perfect companions. However, it’s important for owners to consider their needs, including appropriate living environment, nutrition, and space to wander. Whether as wool producers or beloved pets, the Valais Blacknose sheep have earned their fame in being helpful animals.

Today, the most frightening living shark is the great white, which is over six meters long and bites with a force of two tonnes. Its fossil relative, Megalodon (meaning "big tooth") that lived about 23 to 3.6 million years ago, was over twice the length of a great white shark and had a bite force of more than ten tonnes.

Jack Cooper and his team used a number of mathematical methods to find out the size and proportions(比例)of this monster, by making close comparisons with a variety of living relatives that have certain similarities to Megalodon. He said, “I have always been mad about sharks. Megalodon was actually the very animal that inspired me to pursue palaeontology(古生物学) in the first place when I was just six years old, so I was over the moon to get a chance to study it. This was my dream project.”

Previously the fossil shark, known formally as Otodus megalodon, was only compared with the great white. Jack and his colleagues, for the first time, expanded this analysis to include five modern sharks. “ Megalodon is not a direct ancestor of the great white and is equally related to several modern sharks such as the salmon shark, as well as the great white. We collected detailed measurements of all five to make predictions about Megalodon,”Dr. Pimiento said.

The researchers discovered that the babies of all these modern sharks start out as little adults, and they don’t change in proportion as they get larger. Jack Cooper said, “This means we could simply take the growth curves(生长曲线) of the five modern forms and forecast the overall shape as they get larger and larger--- right up to a body length of 16 meters.”

The results suggest that a 16-meter-long Megalodon likely had a head round 4.65 meters long, a fin about 1.62 meters tall on the back and a tail around 3.85 meters high. The reconstruction of the size of Megalodon’s body parts represents a fundamental step towards a better understanding of this huge extinct shark.

Sucking blood is a risky business. At least for the female mosquitoes that need these nutrients to nurture their developing eggs. Not only do these bugs have to find a suitable blood donor, but once they’ve had their fill, they have to be able to escape undetected—to avoid the big swat. How they finesse this stealthy departure has just been revealed in the Journal of Experimental Biology.

Feasting(饱餐) on an unsuspecting mammal can double a mosquito’s body mass. So how does a fully loaded female heave that added bulk off the skin of her host without triggering its pressure sensors and bringing on that fateful slap? To find out, Florian Muijres of Wageningen University in The Netherlands and his colleagues used cameras that record 13,500 frames per second to capture the takeoff maneuvers of 63 blood-fed malarial mosquitoes.

What they discovered is, when it comes to a soft yet speedy getaway...for female skeeters, the wing’s the thing. With a wingbeat frequency of about 600 beats per second...the insects are able to lift themselves lightly off their host. That approach is the opposite of the one favored by most other winged things, says Muijres.

“When most flying animals when they take off, like birds or a fly for example, they first use their legs to push off very hard, and then when they are in the air, then they start beating their wings and generate aerodynamic lift(气动升力) to be able to fly away. Mosquito does it the other way around. It first starts beating its wings and through the aerodynamic forces these wings generate, their body is being lifted off from the substrate. And then they do gently also push down with their long legs to be able to further power their liftoff. But these forces that are being generated by the legs are relatively small.”

In fact, the faint flutter of a mosquito’s wings produces less than one third of the force exerted by similar-sized but much less subtle fruit flies as they shove off in search of another banana. And even on a full stomach, these bloodsuckers are stunningly fast, says Muijres. “So takeoff phase takes only about 30 milliseconds, which is 10 times faster than how fast we can blink our eye.” And they’re gone before we know what hit us. And before we can hit them.