DaBaby booted his baby mama from his house while she was trying to feed their infant child -- or at least he tried to -- before calling the cops in a nasty fight captured on video.

The rapper filmed part of some sort of altercation Sunday between himself and singer DaniLeigh -- whom he's been seeing on and off for the past handful of years ... and whom he now shares a daughter with, who was born in August.

Unclear what exactly led up to all this ... but at some point in the night, DB started filming DL trying to nurse the kid while in bed, and seemed to be aggravating to the new mother.

DaniLeigh told him to stop, and even tried putting a pillow up between them ... which DaBaby seems to swipe away so she can be in view of the camera. Eventually, DaniLeigh took over from her phone -- and it shows the cops had been called -- apparently at DB's behest.

DaniLeigh goes on an emotional rant -- saying she's getting kicked out of DaBaby's house in North Carolina ... noting she has nowhere to go, but that she'll figure it out.

For DaBaby's part, he tried explaining what was up in a lengthy statement on IG ... which was mostly rambling. But, the gist (from what we can gather) is that he's claiming he's the victim here -- and that DaniLeigh was beating on him and chasing him, like something out of "Fatal Attraction." He says he started filming her for his own protection.

DL was a little more coherent in her own remarks ... saying she's been living with DaBaby since having their kid a few months ago -- and that he randomly asked her to scram last night ... for what she perceives was him wanting to bang another chick.