We sprayed her arse purple. But it's special chicken arse-spray, not something we picked up in the reduced bin at Halfords...
That chook is Adela and sadly, she's at the bottom of the pecking order. This means that all the others beat her up and peck at her. She lost a load of feathers round her backside and it was starting to get very sore. The spray does two things; it's antiseptic and it dyes the area purple.
Chickens are attracted to peck at anything red. By making her arse something other than red, she won't get pecked nearly as much.