Ah, the sounds of morning …
Birds singing,

Photo by Brian Robert Marshall via Wikimedia Commons
tea kettle pouring,

Photo by Patrick George via Wikimedia Commons
and the pelting of peas upon windowpanes.

Photo by Parvathisri via Wikimedia Commons
Curious?
I thought you might be.
Pea pelting was the work of “knocker ups” in England and Ireland before alarm clocks put an end to the profession.
Note, gentle reader, that “knocking up” bore no resemblance to our modern slang terminology (ahem).
In fact, it was a valued service generally provided by elderly women and men, and occasionally undertaken by police constables looking to pad their paychecks during early-morning patrols.
Each morning, the knocker up was charged with rousing sleeping people so they could get to work on time. She would use a heavy stick called a truncheon to knock on clients’ first-floor doors. For residents above arm’s reach, the knocker up would wield a long stick, often made of bamboo, to tap upper-story windows.

Image courtesy of Au Bout de la Route blog
Some of the more adventurous knocker ups, like Mary Smith of London’s Brenton Street (shown below), employed pea shooters to hurl dried peas at windows until the sleeper within woke up.

Image courtesy of Basilica Fields blog
In return for their services, knocker-ups were paid a few pence a week.
Now you know!