You can start litter training your kitten around four weeks of age. At this stage, they begin to develop control over their bladder and bowels, making it easier for them to learn to use the litter box. Provide a low-sided litter box with unscented, clumping litter, and place the kitten inside after meals and naps to encourage proper litter box habits. Positive reinforcement and patience are key to successful litter training.