I found four little kittens about a week-week and half but the mom is always runs off?

If the kittens are eating the food they are most likely 4 weeks old. I would call your local SPCA and gain advice on collecting the kittens so as they may spay and neuter them when they are old enough. Cows milk is very bad for the kittens and may cause life threatening diarrhea so stay away from that.