Superfetate

The hare, for instance, which is hunted alike by beasts, birds, and men, breeds so abundantly as even to superfetate, a thing which is true of no other animal. You find in a hare's belly, at one and the same time, some of the young all covered with fur, others quite naked, others again just fully formed in the womb, while the hare perhaps has lately conceived afresh.

Rabbits breed in every month of the year, and superfetate, as do hares; after giving birth they pair again at once.