This is a kind of protection for the dog for itself
Most animals cannot be played normally when they were born, and some even slowly recovered after 1-2 weeks and then gradually developed. So we saw that the puppies just born could not open their eyes.
In the process of evolution, in order to survive and reproduce each species, they each developed the best way to adapt to the environment, as well as mammals. When producing young children, they faced a two -choice problem -whether to choose longer pregnancy. Time, then the descendants with more comprehensive body development and more organs? Still choose a slightly shorter pregnancy, and then give birth to immature or even partial development, and more descendants need to be taken care of.
In the wild, dogs survive through hunting. Turning up the big belly will slow down the speed of the bitch, making it more difficult for them to catch the fast running prey, so it is difficult to complete the hunting tasks they should have completed in the population. This means that it is more favorable to survive these puppies from the uterus.
In addition, after the hunting (maybe a few days between hunting), the female dogs are almost nothing to do, so the female dogs have more time to take care of the helpless young babies. When she strives to hunt the prey to get food, the young babies who do not run around can also be safely stored in the nest.
The dog's pregnancy period is relatively short, with an average of 58 to 63 days on average in almost two months. The result is that puppies are very helpless. Biologists refer to the species of this kind of immature and dependent dependence as "late -mature species". The root of this word develops from the term "care, feeding, and nourishing" in Latin. This word specifically refers to the feeding and care of the larvae of these species for a long time.
As soon as puppies are born, blindness and deafness are a protection. Many of the key organs of puppies are not fully developed, but they will develop at high speed within a few weeks after puppies are born. The same is true for their eyes. The puppies are closed when they are born because their developing eyes are still extremely weak, and the tight eyelids need to resist the invasion of soil, gravel and pathogens. In addition, the eyes are exposed to too bright light, and it is also easy to hurt their delicate photosensitive cells and eyes.
Most puppies started to open their eyes around the two weeks. Even so, their eyes still did not develop well, their functions did not reach perfection, and their eyes would be thoroughly developed to achieve normal vision level.
Like the eyes closed, the ear canal was blocked at the same time when the dog was born. Relatively quiet is very important for the development of the hearing system, because a strong voice will damage the dog's ears structure. When the puppy's weak hearing system is not fully developed, if they force them to respond to your voice, it is likely that their entire hearing organs will suffer huge damage.
The dog's ear canal opens and the eyes are opened at the same time. Similarly, it takes a few weeks to develop even if the ear canal opens their hearing system. However, after opening the ear canal, it only takes a week, the dog's hearing is completely available and extremely keen. This is why the newborn puppies are "deaf" and "blind".