Spot for cats and rats

ALLEY

Narrow urban passage where strays might scurry between buildings at night.

"Spot for cats and rats" hints at a narrow passageway where you might find both animals. "Alley" fits because it’s a common urban space for strays and pests, but the clue also plays on the word "alley" sounding like "ally"—a clever nod to how cats and rats are often seen as rivals (not allies) in pop culture. The double meaning makes it a smooth crossword trick.