So here is my list of pro and con thoughts. Help me add to either one, please.
In favor of chickens:
They EAT TICKS.
They eat flies and bugs in general.
They turn over garden soil, loosen thatch, and aerate soil.
They eat kitchen scraps that the goats don't.
They provide fresh eggs.
They provide fresh meat [if I can bring myself to take them to slaughter].
My farmsitter peoples think that chickens are cool. (I.E. I won't piss off the peoples by getting more things for which to care when they are sitting.)
Against chickens:
They add 5-10 minutes to my morning outdoor animal chores.
They are [usually] stupid and [possibly] loud.
They attract predators. Most interestingly, there is the possibility of finding snakes in the nest boxes by putting my hands in there.
They get sick and die in smelly and puzzling ways.
They create tons of mud during the winter if they don't have sufficient bedding and/or are moved enough.
They will far outlive their egg production years.