At least bad moods are!
As I always tell my son, there’s a reason it’s called “work.”
If you never encountered a bad attitude or dark mood at the office, they wouldn’t have to pay you.
But this research proves that bad moods are contagious, so when one of your employees is struggling, just be aware that all those that work with him/her may be infected.
It’s called “emotional contagion” and before it spreads throughout your station, take it seriously.
Talk to the employee. Make sure s/he feels heard and understood.
And if the attitude persists, make consequences part of the deal.
You wouldn’t ignore an outbreak of strep throat, would you?