Cat laying on top of bookcase.
Cats are highly territorial, which sometimes causes turf wars in multi-cat households. Every cat needs some space of his own to be happy, and one of the best ways to provide each of your felines with room to roam is to think "up."

Cats naturally adore looking down at others, and by giving your pets plenty of room up above to move about, you're giving each cat some room of his own. Tall furniture with flat tops — such as bookcases or entertainment centers — are ideal, as long as you leave room enough for your cats to play among the decorations. And make sure the areas are stable (won't topple over) and your cat has a safe way to get to it so he won't fall.

Even better: Add tall cat trees to your home, especially those with platforms at the top and cubbyholes for hiding. Cat trees are a great do-it-yourself project, or check garage sales for secondhand ones.