Mind your p's and q's

[shakeitoffshakeacocktail]

Where does the phrase mind your p's and q's come from and what does it mean?

Also where does the saying 'the birds and the bees talk' come from?

Anyone want to add any more?

Apologies if this is the wrong category

Pleases and excuses. Mind your manners, basically.

P's and Q's is Pleases and thank you's, I read somewhere.

And as it's pedants' corner I'm going to say it's Ps and Qs. Standing for Please* *and Thank you, meaning mind your manners (as PP said).

Another suggestion has been pints and quarts.

And since we're in Pedants' corner - no apostrophes. 😬

P - please Q - thank you

mind your Ps and Qs - remember your manners

It's from printing, I think. In the days when type was set by hand, the compositors had to select the letters individually from massive trays of letter blocks, working upside-down and back to front, at speed. Lower case ps and qs were easily confused.

I wonder why they didn't have to mind their bs and ds. Perhaps they did, but it never took off as a saying because 'bs' and 'ds' sound too similar.

I believe that an apostrophe is correct when the meaning is the plural of a lower case letter.

I've never understood where the birds and the bees expression comes from either. Birds and bees do not have sex lives in any way equivalent to humans, with their egg laying and cloacas etc.