What do chipmunks eat?

Today I stayed home with grandma while mom and Will went to Eagle Bend for convention. During lunch today we were sitting at the table eating Chili when grandma asked,
"what do those chipmunks eat?"
I replied, "they eat bird seed". I must have said the word "seed" a little quiet because she looked at me and asked,
"they eat...birds?!"
haha I am thankful that we don't have bird eating chipmunks!