Yeah those sometimes appear near to the end of a plants life cycle if it hasn't been fertilized in a last ditch attempt at seeding itself.
One of the reason that i think that i never get hermies ever is that i always pollinate at least one lil baby nugget on the lower branch.
Females are happy then and don't panic if you know what i mean and i can keep em flowering for a bit longer if i want really stoney pot.
I may be wrong as i have no evidence of this but its what i do,i always take at least 10 seeds of each plant and it makes no difference to the quality of the bud by just seeding a small lower nugget