A cat without claws can't kill birds. They may not have razor-sharp claws to grab hold of the prey, but a clawless cat can use its agile front legs to deliver a stunning blow with its foot and its sharp teeth to bite into the prey's neck. Kittens must be taught to hunt by their mother. Kittens are born with the instinct to hunt. However, they often become more efficient hunters if the mother shows them how.
Domestic cats are too lazy to hunt.
Cats sleep two-thirds of the day but they are always on alert. Cats rest a lot because they are not designed for endurance. They use high levels of energy for short periods, then rest to recover. Even when they appear to be snoozing, they are light sleepers and alert to sounds and movement around them. Cats prefer catching rodents.