Wiktionary
birds and bees
n. (context idiomatic euphemistic English) informal sex education, especially describing the sexual activity of animals rather than that of people.
Wikipedia
Birds and Bees
Usage examples of "birds and bees".
A blessed haze lies upon all this region, wherein is held a little more of the sunlight than other places hold, and a little more of the summer's humming music of birds and bees.
But he remembered it again when he walked down a white path toward a red-roofed pagoda, and would have questioned the people of this land about it, had he not found that there were no people there, but only birds and bees and butterflies.