How can cats let you know if the dont like onother cat in there household?

Answer 1

Generally a cat will act directly against the other cat when one is introduced to her household. The two cats will challenge each other (staring contests, yowling, and feint rushes), and may actually eventually fight. It is wise to have a place of refuge prepared for the new cat during the introduction process, as the two almost certainly will not get along, at least at first; cats survive in the wild by setting up exclusive hunting grounds, and an invader on their turf can halve their food supply and allow them to starve. The defence of home turf against an invader is instinct and not easily overcome.