What could be the reason why my cats' pee smells like ammonia?

The reason why your cats' pee smells like ammonia could be due to a high concentration of urea in their urine, which can give off an ammonia-like odor. This could be caused by factors such as dehydration, diet, or underlying health issues. It is important to monitor your cats' water intake and consult a veterinarian if you notice any changes in their urine odor.