It's my general policy to be nice to strangers. You never know what they're like.
So when people shout at me in the streets, I say politely hello.
So when the hobo's at my door start talking to me while moving my stuff i say: yes indeed it it warm in black clothes. I am doing fine, how are you? etc etc. Do not keep up conversation, but try to answer as shortly as possible while still being polite.
It starts being anoying when the yesterday's hobo's are here again, and they start shouting:
Hee you were here yesterday. You should have moved by now.
I say yes I should have. But then I went inside and he gave me an entire lecture from the other side of the door. I stopped listening. Sometimes I wish I did not have the you can talk to me and I'll listen appearance. For now I have to go outside and get two shopping carts to move my stuff tomorrow but I guess when I enter the building with those things I am definitely in his area of expertese so maybe I'll wait till he's gone...