I’ve been seeing small 3-5 ft diameter circles of water that are smoother than the other surface water near my fishing spot. They don’t last long, maybe a few minutes. I’ve googled several times but can’t find a good answer. Are these fish swimming around under the surface causing a disturbance? Or some sort of under water current? I’ve tried casting out to those spots with some top water plugs/poppers but I haven’t gotten any bites.

thanks in advance from a newbie angler

A picture is worth 10,000 words. No idea what your describing, and it could a number of things. 

I thought for years it was fish sucking bugs from the surface. Then I was walking my dog around a park pond and saw bugs dancing across the surface…making the same exact circles. 
 

So now I’m pretty sold that they’re actually just tiny insects dipping water at the surface. But hey, bugs attract small fish that attract big fish. So it all comes out in the wash. 

Up north its some kind of water bug that swims in circles. On calm water they are easy to see.

I've seen water bugs do this as Dave and huZZah described, and balls of little young of the year shad at the surface create slick spots as well.

Sounds similar to crop circles so it must be aliens.  ?

51 minutes ago, Tennessee Boy said:

Sounds similar to crop circles so it must be aliens.  ?