Both the Yorks are belled; the other dogs are larger and easily seen. Besides, when they're outside in the yard, they're easier to find when they go Ninja on me.
I also have pet stairs - a set in the living room so they can run the furniture, and a set in the bedroom. Puddie will jump up/down off the living room furniture if he feels like it, but only uses the stairs in the bedroom. Bella has never used anything BUT stairs - in fact, I can trap her on the furniture: she won't jump off no matter what - in fact WHINES - if the stairs get moved.
Puddie weighs 7 lbs; Bella's at 4 lbs. But my grandson's Westie is 15 lbs., and the other resident beastie is a 70 lb. pitty. All play fantastically, and if the truth be known, Bella rules the roost: no one told her she's the smallest