2 of my hens laid 2 small eggs don't know why

[MamaBear2016]

what is causing 2 of hens or 1 of them is giving me small eggs
i added two pictures up one is the regular eggs i get the small light
tan one is from one of hens ,
i have 2 rhode island reds and 2 easter layers
i just getting the small ones .does anyone know why i am getting
small eggs that are a size of a marble ?

 

[floppysquirrel04]

How old is the hen in question? What are you feeding them?

 

[MamaBear2016]

they are almost 1 years old i was getting 1 to 4 eggs a day the food i give them is
DuMor poultry 16% egg laying pellets and they would get once in awhile fresh worms from my yard and they were laying lots then too and i had gotten them some Flock party oat & mealworms but my hens start or started doing the small egg laying 5 days before one of them started doing this i have the roosters in a pin next to my hens where they can see each other
I get their feed from Tractor Supply Co. where my son works