Lump on back end of 4 wk old chick

[Lcosper8]

Noticed today that one of my 4 wk old chicks has a lump the size of a ping pong ball on her back end. It's about an inch to the left, and inch below the vent. I've noticed some other tissue protruding from the lump to down under her belly. She seems to be eating, drinking & pooping fine and acts normal. She does react when I gently touch the lump. I didn't find any scabs or puncture marks to indicate that it is an abcessed wound.

I would appreciate any help in figuring out what this out and if there's anything I can do.
Thanks!

 

[Nsampsel]

Could it be a hernia...hard to see from the pix. Maybe some closer ones with better lighting would help

 

[Lcosper8]

I'll try to get a better pic.
You can see it moving in and out as she breathes. Strange. She is still acting just fine, though.

 

[Lcosper8]

I've looked at some pics of other chickens w/ hernias and I'm certain that is what she has! Thank you for bringing it up. Hernia didn't even occur to me.