Hi Zack,
Project is at work.
You have certainly entered things like dependencies, or even put leveling to
automatic.
And look, this is what Project is made for, to recalculate plans based on
your input.
If ou really want to, you can kill its enthousiastic behaviour:
Tools, resource leveling, put to LMManual instead of automatic (always a
decent advice)
Tools, Options, Calculation, put Calculation to manual. Bad advice; betetr
use visio to draw charts, they won't move either.
HTH