mud, my hens love to eat mud , im shur there is something in there they need but idk what it is but they love it ........ all my birds love it chickens ducks geese and turkeys all eat it
my geese like to eat the seeds off of foxtail grass , in the fall they will fight each other for the crab apples off the trees lol we like to pick them and toss them and watch all the birds run after them. thts all i can think of i hope it helps