Blood in window

[NorthernSkies]

Hi all,
I live in an apartment and feed grey squirrels and purposely left a crack between the two Windows for a squirrel to make a nest. I also left pillow stuffing in there and a black squirrel has been there all winter. Recently I noticed dried and smeared blood on the window on its way out. None in the nest. I have been curious and worried. Other squirrels come between the windows to eat... This morning I noticed the black squirrel had another squirrel in its nest and was grooming it. I don't know if by force or anything but next thing I know that squirrel bolted out and there was a bloody print on the wall leading out. I am very puzzled about this situation. Is the black squirrel an agressor or is he sick or fighting or what..... Thank you

[SammysMom]

That is odd. You see blood, but you haven't been able to see if there is a would of some sort? How long have you been seeing the blood?

[NorthernSkies]

Well about 3 days since I haven't cleaned it yet but I think there's a new spot today

[NorthernSkies]

I haven't been able to post a picture apparently. He does have fur missing in his back (I'm just supposing it's a male)
But no apprarent wound. Why is he grooming the other squirrel in his nest and then that squirrel bolting out? Is it friendly or domination?