We all know that zebras have stripes (条纹). However, both animal experts and zebra fans all over the world haven't known the reason for centuries. But now it appears that some researchers in California may have finally solved the age-old mystery!

    In order to find the reason why zebras have stripes, a team of scientists led by Professor Tim Caro set to work. They began by comparing the thickness, location, and the stripes on seven species of zebras that live in various geographic locations. They then examined some factors that may continuously affect zebras, such as their natural enemies, the temperatures of their living places and the small insects around them like flies. To their amazement, the only factor that was linked with the stripes was the annoying flies. The zebras with the most obvious and the largest number of stripes mostly live in areas with more flies.

    But that led to another question: why are zebras the only kind of animal smart enough to develop the stripes? After all, there are plenty of other animals like horses and donkeys, which are facing the same trouble. Upon closer examination of the black and white animals, the researchers noticed that unlike the others, zebras have very short coats of hair, making them particularly easy to be bitten (咬) by the flies!

    While Tim says that this mystery is finally solved, it has given rise to a new one. Why are these fearless flies that have no fears of attacking animals that are thousands of times bigger, afraid of black and white stripes? If you have any answer, be sure to add it to the comments below. It may help the professor with his new research!