Trail of moving object in saved pcd

[lookquad]

Hi

When i run the mapping and visualise the result in rviz, it looks fine with no trail of any moving objects like a person. But when i save the point cloud as a pcd and visualise it using cloud compare, i can see the trail of all the moving persons.

My query is :
Why there is a trail in saved PCD
how can i avoid that trail from saving into PCD.

Thank You!