That's exactly what I dealt with yesterday, when a Mennonite neighbor called me about a little kitten in the woods behind her house. It was hiding in a fallen rotten tree trunk. I had to chase the little fluffer but eventually got it and put it in the garage with my other residents for the night.
I took it (named it Baby because it is only weeks old) to the vet to be checked out (with another colony teen to be neutered). Baby is a silver kitten with longer hair. Incredibly cute. Looks like a little ball of floof with the thicker coat already setting in. I didn't need another cat, but of course couldn't leave it behind. No momma in sight. Non of mine have taken it in that I can tell, so I will have to bottle feed it for a while to fatten it up before winter.