It's(from oldest to youngest) 1 Alvin 2 Simon 3 Theodore.

I'm not trying to be rude,but I noticed that during the story

AWSUM!

one jeanette is yonger than brittney. in may the best chipmunk win brittney said my little sister jeanette has brought my life to an end. Same for simon. in grouned chipmunk alvin said i've never been alone execpt those first five mins before simon was born. alvin simon theodore brittney jeanette and eleanor. hope that helps.