I think he may have nesting and roosting crossed up. The nest is where they lay their eggs, and they do that on the ground or a nest box if you have them pend up.
Next he has to be feeding them or they started coming around when they were young.
I gave some grown ones to my neighbor once, about 300 yds up the road, next day they came walking down the road back home.
Guineas are one fowl that hasn't been tamed, they have only been domesticated, just like honey bees.
Been there, done that.
For yard birds, I prefer Guineas, they will get rid of ticks and don't eat as much garden as chickens.
Been there done that to.
They are also good guard dogs, if anything strange comes around they will let you know.
Been there done that also.
There are also other places I have been and things I have done.