@Linkat,
They are streetfighting cats and dogs- I was thinking their HQ would in an alleyway somewhere underground. They could activate a trap door to it by lifting up a trash can lid with a wire on the inside of it which causes a trap door to open on the side of a dumpster, or on the ground, or somewhere in that vicinity, and the trap door leads to their underground HQ.
I was trying to come up with something with a cat- and dog-themed feel to it.