When kitty litter gets wet, it absorbs and clumps around the moisture. This is especially true for clumping cat litters, which form solid clumps when they come into contact with urine. Non-clumping litters may become heavy and form clumps, making it easier to scoop waste. Some cat litters are designed to neutralize odors as they absorb moisture, helping to keep the litter box smelling fresh. It's essential to regularly scoop out soiled litter and replace it with fresh litter to maintain a clean and odor-free litter box.