Rats has been a problem in the DC area for about 20 years.
My daughter and I walked into our garage one day and a black rat ran out after munching on spilled grass seed. My daughter was in kindergarten but yelled out “A black rat! The plague!!”
How in the heck she knew this I’ll never know. But it was a hoot.
The worst rat problem I ever saw was in Japanese food markets. Rats all over the place. Didn’t buy anything.
When I was in college in the 70s I was waiting for a DC bus on Monroe Street near Catholic University. Walking out of a drainage pipe right next to the bus stop was a rat. I could have sworn he looked up at me, shrugged his shoulders, and sauntered off the sidewalk, continuing on his way across the street.
I'm laying the blame on the Carter Administration. I'm guessing Jimmy listened to his idiot daughter, and stopped the use of rat poison in the WH.
That set a trend.
Heck, I'll even guess that Uncle Billy was smart enough to turn his beer cans into rat traps, safely and appropriately.