Wanting to befriend a crow

For a while now, I suspect I have a crow visiting my porch. I have some string lights wrapped around the railing, and in one spot (the same every time), there is grass tucked under the lights. I'll clean it off and it will reappear a week or two later.

Lately, I have been finding rocks left on the porch. They are some very distinctive rocks I have at one part of my driveway.

The problem is, I also have a LOT of squirrels around and I know for sure, if I put out food to attract the crows, the squirrels will get to it first. They are relentless!

Is there anything else I could put out that would interest the crows, but not the squirrels?

Thanks!!