Final answer:
Millipedes walk smoothly compared to centipedes because they have more legs, which provide better stability and weight distribution.
Step-by-step explanation:
Millipedes walk smoothly compared to centipedes because they have two pairs of legs per body segment, while centipedes have only one pair. This means that millipedes have more legs in total, which allows for a smoother and more coordinated movement. The extra legs help distribute the weight evenly and provide better stability, resulting in a smoother walk.