Breast injury

[Swiftbug2]

Anyone got an idea what im looking at? Was treating my flock for hen fleas when i came across this one. Suggested treatments? Its hardened. Shes acting normal from what i can tell

 

[Wyorp Rock]

Looks like a breast blister.


https://www.backyardchickens.com/threads/bumble-breast-breast-blister-graphic-pictures.1096276/

https://poultrydvm.com/condition/breast-blister