I need to find and buy some more of these for certain projects but I don't know what they're called and how easy they are to buy? I use them on each end of birdhouse s I make to hang them.

Drive rings - phone companies use them and some electrical contractors.
I doubt Lowes or Home Depot would have them. Try an electrical supply store that serves contractors.

here

That was fast. That's why I like this place.

Thanks a lot! That is what I wanted to know. The ones I was using looked quite old, I was hoping they were Not something vintage and out of make.

What a difference in price between those two sites.
The lerge one looks like a telephone home hook-up bracket