Loose impediments

You may remove a loose impediment without penalty anywhere on or off the course, and may do so in any way (such as by using your hand or foot or using a club or other equipment). But if your removal of a loose impediment causes your ball to move, your ball must be replaced on its original spot (which if not known must be estimated).

If your moved ball had been at rest anywhere except on the putting green or in the teeing area, you get one penalty stroke.

There are two exceptions when you may not remove a loose impediment: Exception 1 – Removing Loose Impediment Where Ball Must Be Replaced. Exception 2 – Restrictions on Deliberately Removing Loose Impediments to Affect Ball in Motion.

Related Rule - 15.1