In the initial cognition, people usually judge the intelligence of cats and dogs based on brain neurons. Cats have 300 million neurons in their brains, and dogs have 160 million. Many people think that cats are smarter than dogs. In fact, this is not the case. The latest scientific research shows that cats are not as smart as people think, nor are they as smart as dogs. Scientists conducted an experiment on 15 cats to obtain food. They tied the food to the end of a long rope and observed whether the cats would pull the food to themselves by pulling on the rope. It turned out that when there was only one long rope, the cats had no problem getting food. But if faced with more than two ropes, the cat will not know how to "concentrate" on pulling one of the ropes to obtain food. Cats fared worse than dogs, who could at least solve the problem of two parallel ropes. This experiment proves that cats cannot understand the "causal" relationship between things.