  In this paper, mechanical models with Newton's Law of impacts are studied.
One of the most interesting properties in some of these models is chattering.
This phenomenon is understood as the appearance of an infinite number of
impacts occurring in a finite time. Conclusion on the presence of chattering is
made exclusively by examination of the right hand side of impact models for the
first time. Criteria for the sets of initial data which always lead to
chattering are established. The Moon-Holmes model is subject to regular impact
perturbations for the chattering generation. Using the chattering solutions,
continuous chattering is generated. To depress the chattering, Pyragas control
is applied. Illustrative examples are provided to demonstrate the impact
chattering.
