Eggs. Period.

Me: Why do birds lay unfertilised eggs, anyway?

Colleague: They’re basically birds’ periods.

Me: You don’t often hear eggs described that way, do you? “Go to work on a bird’s period.”

Me: Why do birds lay unfertilised eggs, anyway?
Colleague: They’re basically birds’ periods.
Me: You don’t often hear eggs described that way, do you? “Go to work on a bird’s period.”