Very well putHello and welcome to BYC!Glad you joined.
I did read the letter. It does not appear as if John has ever owned chickens.
As @N F C and @janiedoe have explained, chicken coops are only as dirty as the owners allow them to be and a great deal of that has to do with the number of birds kept within a specified amount of space. I have owned chickens for nearly 5 years and I've never had a rodent problem. Yes, I have had mice but that is because I have gaps between the frame and the door to the run wider than a half inch and I don't pick up the chicken food.
Quite the contrary to all the complaints John has to say about chickens, they can be quite relaxing and beautiful to just sit and watch and can add a lovely aesthetic to a community. Additionally he's wrong about the dumping open garbage. That, again, is up to the caregiver. And as for the extreme amount of care that they need? They're one of the easiest animals to keep when kept in a properly designed and sized coop and run. A dog requires more work than chickens.
