Cats are naturally solitary animals and are often happy without the company of their own species. They are territorial animals who don’t like conflict with other cats.
Related cats tend to get on better than those who aren’t family, so getting littermates is best if you want more than one cat
Having more than one cat at home is cute but please don’t ignore your fur friend’s feelings, he/she might face depression like us. It takes time for the cat to befriend with the new cat as he thinks he’s no longer the boss of the house and another cat is occupying his space. He might be angry, hiding, and loss of appetite.Therefore, patience is needed!
Some little tips to improve their relationship:
Provide one litter tray per cat, plus one more, to keep all your cats happy
Brush/Groom their hair with the same brush to make them familiar with others.
Always feed the old cat first, so they know their places in the house
Things to avoid:
Force them to be together
Only shower one of the cat (the other cat might forget the smell of the other and start fighting over again as he thought other cat has enter the house)