I believe you have until May 22 to enter code ITSMOMSDAY2SHINE for 50 free Kellogg's points. Man, I don't know how Kellogg's can afford to keep doling out so many high valued codes at this pace. It's almost as if these points have no intrinsic value! What a freebie for Mother's Day.
If you're reading this post after the codes above have expired, fret not! I keep a running, updated list of all free Kellogg's codes currently active.