I feed 1tsp for dwarf & 2tsp for Syrian per day too & I leave it down til it's gone to avoid selective feeding. They always take their favourites first...
I think your hammies are having great fun stashing food somewhere & definitely don't need that much. I find on a day that I feed a treat (stick of millet or something) they will take less mix anyway. Don't give too many treats or they won't be getting a balanced diet.
Hope you are enjoying your new hammies
