As long as these vents aren't taking over every other comment or story that a coworker shares, sometimes a coworker just needs you to listen first.
Asking me "Are you going home?" at the end of work day as a set up to enlist me to help you with a task you're working on. Clever guise, but annoying. If you know you have a program/volunteer event going on in advance, and typically you do, let me know in advance.
For mirrored post, see modeling behavior from coworkers.