strange behavior?

[Uncle Chester]

As part of our family flock of chickens & ducks we had 2 guinea hens. One died this week.
Now the other one is tormenting the others...especially my roosters. He/she chases the roosters and grabs their tail feathers. My roosters don't even want to come in out of the rain when this guinea is in the coop.
Any explanation?
Thanks ahead of time!
Uncle Chester the Goat

 

[Fluffychicky]

If it's a male maybe the other guinea was it's flock/mate and now that it's gone it's trying to take over the rooster's flock? I'm not all that sure but that's my best bet.