Another way to make life more fulfilling for cats: Enrich the environment. Cats like to look out windows and see birds, Dr. Houpt says. They will greatly appreciate a viewing perch, such as a cat tree. You can also simulate outdoor life by playing games that allow them to stalk and hunt prey-such as a tossed catnip mouse or a wand with dangling feathers like Da Bird. I also recommend the CatDancer, a bouncy wire with rugged cardboard dangles, which moves in intriguingly erratic ways. Laser pointers make a dot of light that owners can wave for their cats to chase. And treat balls with holes that release kibble when batted around can keep life interesting while you are away.