The hydrant begins to yell, "Why you little stoner fool! I hate you f***ed-up sons of b****es who just come around here looking for s*** to smoke at my f***ing expense..." He then goes off into a long rant about how bad pot is.

Of course, being a stoner alien, you don't listen to him. You are also turned away by the fact that the hydrant begins to throw government propaganda pamphlets at you.

It looks like your mission of first contact has just gone very bad.