Tigers and lions are nocturnal animals. At night, the light is weak, but they can still go out to hunt. What is the reason? It turns out that the retina behind an animal's eyeball is composed of cylindrical or conical cells. Cylindrical cells are suitable for sensing objects in weak light, while conical cells are suitable for sensing objects in strong light. In the retina of Nocturnal Animals, such as tigers and lions, cylindrical cells are dominant. At night, their eyes are the brightest and stare the biggest, with a diameter of three or four centimeters. So, although the light is very weak, we can see it clearly.
In winter, when cats sleep, they always try to shrink their bodies into spheres. Why? It turns out that there is a principle in mathematics that the surface area of a ball is the smallest among objects of the same volume. The body size of a cat is certain. In order to minimize the heat loss when sleeping in winter and keep the temperature in the body as little as possible, cats skillfully "use" this geometric attribute.
We all know that fleas are "high jump champions". 19 10 years, Americans did an experiment and found that a flea can jump 33 cm away and 19.69 cm high. This height is equivalent to 130 times of his body length. According to this ratio, if an adult with a height of 1.70 meters can jump like a flea, then he can jump 22 1 meter, which is equivalent to the height of 70 floors.
Ants are industrious and gregarious insects. A British man named Henston once did an experiment: cut a dead grasshopper into three pieces. The second block is twice as big as the first block, and the third block is twice as big as the second block. When ants organize labor to carry these foods, the latter group is about twice as large as the former group. It seems that it also knows the laws of geometric series!
Birch leaf curl weevil can make a conical "delivery room" from birch leaves. It bites birch leaves like this: when the female weevil starts to work, she first climbs to a place not far from the petiole, bites through the leaves with her sharp jaw, and retreats to bite out the first arc crack. Then climb to the other side of the leaf and bite out a curve with less curvature. Then go back to the beginning and roll the lower part of the leaf into a very thin cone and turn it for 5 ~ 7 times. Then roll the other half into a conical cylinder in the opposite direction, thus making a solid "delivery room".