Why can't humans successfully translate animal languages?

Human language is slowly changing from an unconscious ape to words and sentences, and finally people living together are unified and have dialects. Things in life are recorded by symbols, with words. With the integration of groups, different dialects and characters gradually merge, and finally more mature languages are used, while the languages of other animals are often simpler, which is subject to the IQ of animals. The formation of human wisdom and language depends on the brain developed slowly after liberating hands. There are also some animals whose IQ is insufficient and their language cannot be developed too maturely, such as cats and dogs at home. Some are really smart, such as whales, dolphins, apes and elephants. Their languages have hundreds of meanings, but their languages are not easy to understand. They may be easy to understand. This may sound confusing to humans themselves. People's hearing and body language are different from cats and dogs. Thousands of years' experience tells us that dogs wag their tails when they are happy and cats snore when they are happy, but their cries are different. After getting along for a long time, I can't hear it at all, and hearing it may not necessarily apply to other cats and dogs. Maybe even people's crying is meaningless, for example, uh-oh, uh-oh, can you translate it? Our familiar cats and dogs can only be translated into this way, and unfamiliar animals are even more blind. Therefore, even for other animals with high IQ, there is still no universal standard for language, so it is too difficult for people to compile books and books in animal languages and translate them into human languages, and they can only do so reluctantly.