People who keep cats often plan to raise another after having one, so the two can play together and have company, which can also improve their personalities. However, cats are animals with strong territorial instincts, so we need to consider more about how to let the old cat accept the new one.

　　First, the new cat’s age and size should preferably be smaller. This way, the cat at home will not feel threatened, opening the first step to harmonious coexistence.

　　Secondly, it’s best to avoid having both cats be males. Even if two male cats get along harmoniously during kittenhood, you cannot be careless. When both males mature, aggressive behaviors may still occur. Therefore, it’s best to avoid such combinations when choosing a new cat.

　　The personalities of the two cats should not differ too much. If the new cat is too lively, it can make the introverted old cat nervous, leading to aggressive behaviors.

　　The new cat just brought home needs to get familiar with the environment and the owner first. So don’t let the two cats meet immediately. Quarantine for one to two weeks to avoid possible disease transmission from the new cat. During this time, the owner should accompany the new cat daily, letting it accept you first to lay the foundation for future meetings.

　　Next is the introduction, but the owner must not rush and should proceed slowly. First, bring items with the new cat’s scent to the other cat, allowing it to gradually get used to and stop rejecting it. When the new cat, now familiar with the owner, can be brought out of the room to meet, the meeting times should increase step-by-step, observing if there is any mutual aggression. If the initial meeting does not go well, bring the new cat back and replace the initial door isolation with a screen door or similar barrier that allows meeting but prevents attacks. Increasing mutual interaction during feeding times with food can reduce hostility, and afterwards, the two cats can gradually get along well.