Setup for ambient motion on many shapes

Hi, I'm using CS6 and am a complete noob so this may be really obvious.

I have a grid of small squares that I'd like to animate with an ambient "breath" cycle. I know I could move them individually. I'd like to figure out how to set up a larger group, rig, or lattice. Then I could use that animation and change the number of squares.

I roughed the idea by selecting and transforming all 28 squares. This scales each shape nonuniformly and is only in 2 axes.

Thanks so much for your help!

Attachment 74117

you could scale up container and move it up-left at the same time