Using Bragg scattering we study classical squeezing and wave packet os
cillations of the atomic center-of-mass motion of cesium atoms trapped
in 1D and 3D optical lattices. A sudden increase of the potential dep
th leads to wave packets substantially more localized than in steady s
tate, and subsequent breathing-mode oscillations with a decay rate tha
t under some conditions is remarkably slow. We also study the response
of the atoms to parametric driving of the center-of-mass motion. Our
results are in agreement with Monte Carlo simulations.