You should actively engage your cat at least a couple of times a day with some predator-prey activity, such as chasing foil balls or chasing a feather lure on a stringed pole, to avoid a bored cat. For self-motivated entertainment, there are a variety of soft toys, balls, mice to chase. Cats love to hide and pounce. Give them a box with some random holes cut in it, or a good old paper bag.