There is a bulging thing near the frog's mouth, which can make a sound. It likes to sing loudly on rainy days in summer. In hot summer, frogs usually hide in the grass and shout occasionally for a short time. The following is why frogs bark when it rains. It's for reference only. Welcome to read it!
Why do frogs bark when it rains
Every rainy day, frogs bark very loudly. Especially when it's going to rain, the frogs Cry one after another, louder and louder. It's like a concert.
Frogs don't like living in too cold, too hot or too dry environment. They like cool and humid places, so when it rains, it's really fun for frogs. Especially after a period of sunny and dry days, when it is going to rain, because the air pressure drops, the humidity increases, the moisture in the air increases, and the frog's skin is fully wet, so it becomes active.
At the same time, in the rainy season, many insects breed in large numbers at this time. These insects are the food of frogs. At this time, frogs have just passed the cold and dry winter. They need to prey on insects in order to recover their strength. When there is good food and good environment, frogs can't help singing loudly; Taking this opportunity, male and female frogs also mate and reproduce by the water side of the pool.
It's very hot on a summer night. From the field came the cries of frogs: "quack - quack - quack", "quack - quack - quack". This kind of animal chorus often rises one after another and reverberates in the night sky all night.
Frogs are amphibians, that is, they can live both in water and on land. However, the little tadpoles that have not yet become frogs cannot live without water, because they breathe with gills like fish. After the tadpoles grow into frogs, they gradually get used to breathing with their lungs, so that they can live on land.
Although frogs are amphibians, they seem to prefer life in the water. We can often see frogs at the water's edge jumping into the water "plop, plop", and then jumping onto the shore or lotus leaves. At least, frogs like the humid environment very much. Therefore, before it rains, the humidity in the air becomes higher and higher. At this time, the frogs in the field will "happily" scream. When the rain fell, the frogs in the pond jumped up and down happily and kept busy.
Why can Eagles find small prey on the ground from high altitude
Eagle is the general name of Falconidae birds, such as sparrow hawk, Black Kite, Golden Eagle, vulture and so on. Eagles are birds of prey that move during the day. They mainly feed on small birds, animals and frogs, but the food of different kinds of eagles varies greatly. In sunny weather, the heated air will form a rising hot air flow, and eagles can hover in the air through the hot air flow. This kind of hot air flow is strongest on the ridge. Therefore, on the top of the mountain in the suburbs, we can often see the figure of eagles hovering at high altitude. Their free flying appearance is very comfortable.
The main purpose of the eagle circling at high altitude is to hunt. However, although the high altitude has a wide field of vision, it is far from the ground after all. Why can the eagle easily find rats, rabbits and other small birds and animals on the ground? This is because eagles have special eyesight. An adult with normal eyesight can only distinguish objects more than 10cm away from 100 meters. The eyesight of eagles is at least three times sharper than that of humans. They can also distinguish small animals moving on the ground when hovering at an altitude of about 1000 meters above the ground.
Generally speaking, birds have good eyesight. The secret lies in their eyes. Current research has proved that Eagles not only see farther than humans, but also have a wider range of color vision than humans. They can see ultraviolet light that we can't see. The human retina has only hundreds of thousands of photoreceptor cells per square millimeter, while large eagles, such as ordinary birds, have up to 1 million photoreceptor cells per square millimeter in their eyes. More specifically, birds' eyes usually grow on both sides of the head (except owls of the order OWL), which means that they have a larger field of view, and some birds can reach 300 °. Moreover, birds have developed muscle tissue around their eyes, which can change the shape of the eye lens in a very short time to achieve rapid focusing.
Human eyes account for less than 5% of the volume of the head, while birds account for 20% ~ 25%. As a top predator, the eagle's eye size is even more prominent among many birds. Their eyes are almost as big as those of humans. With large eyes, high-density photoreceptor cells, large visual field and developed nerve and muscle tissues around the eyes, the eagle has extraordinary vision and makes it a overlord in the air.
Why do flowers love to stick their leaves out of the window
If you plant ornamental flowers in your home and put them near the window, you will find a very interesting phenomenon that their leaves will grow towards the window, as if full of the desire to extend out of the window. It seems that plants do not need enough sunlight to produce nutrients themselves. If you compare the outside of the window with the inside of the room, of course, plants choose the former, because they can bathe in more sunshine outside the window. However, unlike human hands, plant leaves can move freely. So who will help plant leaves pursue sunshine? This question is up to scientists to answer.
Long ago, Darwin, the pioneer of evolution, had noticed that when the seedlings of indoor plants broke through the soil, they all tilted towards the transparent glass window. He thought that there might be something in the plant that controls the light movement of the plant. According to his intuition, Darwin thought it might be near the top bud of the plant, so he cut off a piece of the top bud of the seedling, and the situation changed completely. Although the seedlings continue to grow upward, they will no longer tilt to the relatively sunny windows. The experiment convinced Darwin that there must be a magical substance controlling the direction of plant growth. Unfortunately, under the research conditions at that time, Darwin died before he found this substance.
It was not until 1928 that winter, a Dutch American plant physiologist, finally discovered this magical substance. Winter designed a very illustrative experiment. He exposed one side of the plant's coleoptile to light and the other to darkness. As a result, the growth of the coleoptile changed interestingly and gradually bent in the direction of light. Next, winter began to conduct a comprehensive analysis of the substances in the coleoptile, and finally isolated a compound, which is now the famous plant auxin. Through further research, it is found that auxin has the function of promoting plant growth. When the coleoptile is exposed to light, auxin is like a little guy afraid of bright, hiding on the other side of the shade. With the increasing accumulation of auxin on the shaded side, the growth rate of this side is greatly accelerated, while the light receiving side grows slowly due to the lack of auxin, resulting in the bending growth of coleoptile. Therefore, winter believes that the phototropic bending growth of plant stems or leaves is caused by the uneven distribution of auxin in tissues.
Now it's finally clear that indoor flowers love to stick their leaves out of the window. It turns out that they are controlled by auxin.