For each humanity used, the number on the left upper corner climbs.
The chance of discovering items upon killing enemies is higher.

Do we lose it when we die, like the ember in DS3?

I've been farming the Depths bonfire by the big rat that was in the sewer for humanity. At least 9 rats spawn in groups and 1 in the crate. You can just run down, kill them, and run back to the fire and reset. I'm using the Covetous Serpent ring, which is probably the best item in the game. The farm starts out pretty slow at 1 humanity per 3-4 runs but just use the humanity every time you get it until you have 10 and your item discovery is 410, I get about 1 humanity every 1-2 runs average. For some reason, Humanity is just super rare, unless you actually find people that will summon you on boss fights (Which is limited by level, btw.). Or unless you are a god and never die in the game.

For anyone who cares enough this is my data set for depths rat farming with Covetous ring and 10 humanity (410 item discovery)

Since this is one of limited consumables, I did not use them, lol, you know because they are limited... I am about to complete NG+ and I have TONS of humanity in my bag, maybe I will give em to frampt on NG+2 to feed him. I prefer looking hollow wearing hollow soldier armor along with a *****ing ultra greatsword. No humanity needed.

if you dislike this comment I will pull you foot at night

You guys have no idea about Dark Souls until you play the original version, on disk, no internet and no patches. Thats where to find the best dark souls experience

Need humanity

rat ranchers unite