What is this lump??

[Albertxy]

So I just saw my hen picking at this.Any idea what it is or if it's harmful? Can it be treated? Or is it Normal?

 

[Eggcessive]

It looks like the preen gland near the base of the tail. They preen themselves with oil when they touch it. There may be something irritating her or she has been pecked there. I would look for any drainage or swelling later. They can get impacted and infected. Look her over for lice and mites under her belly. Here is some info on the preen gland:
http://www.poultrydvm.com/condition/uropygial-gland-infections

 

[Albertxy]

I looked for mites or live and didn't see any but thank you for your help I will definitely keep an eye on it

 

[Eggcessive]

Since it has a little blood on it, watch that the other chickens do not peck at it. If you have gentian violet, BluKote, or even a little blue food coloring, you could apply a dot to disguise the red color.