Since cave men era, cat has been one of our favorite pet and companion. In Chinese legend, cat and mouse were best of friends. However, when the Lord decided to choose twelve animals to represent the Zodiacs, the mouse misinformed the cat about the date. The cat showed up one day late, and was excluded from the selection. The mouse winded up to be the first animal on the chart. This is why cat hates mouse and the cat is forever chasing the mouse!