This may be the role reversal to end all role reversals.
Scientists Thursday described four insect species that dwell in extremely dry caves in Brazil, feed on bat guano and possess what the researchers called an "evolutionary novelty."
The females have an elaborate, penislike organ, while the males have a vaginalike opening into which females insert their organ during mating sessions that last 40 to 70 hours, the scientists reported in the journal Current Biology.
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