Well, the word "several" I got from high school (amazing what is recalled over the decades), and now the best I can reference would a "possible" binary system at Sagittarius Sgr A, where any radio sources from the supposed partner would likely be skewed by the larger of the two. The larger would be referred to as supermassive black hole (AKA SMBH), being hundreds of thousands to billions of Solar masses, that being our local sun, with the smaller being rendered utterly invisible -- an exercise for high mathematical theory.

Still, with the count of 1 SMBH, and the possibility of at least 1 smaller, though unobservable partner, this opens the question as to whether there might be several equally unobservable black holes viciously spinning around out there, all of which falls to the fanciful realm of speculative sci-fi -- or theoretical astronomy and black hole mechanics.

Do black holes eat black holes, and how messy is that? Are they violently repelled? Are they violently attracted?

Hm-m-m. Just a few million years to find out.

I have no evidence of multiple black holes at Sagittarius Sgr A, ER. Sorry 'bout that.