I see stuff like that all the time and don't think much about it. It's something that is right against the lens. Could be part of a spider web.
Bats in trail cam pics are strange. Looks like something out of this world until you realize what it is.
I've had some pictures where it looked like someone had a bright light approx 100 yards away, and it would move around a little bit. After hundreds of pictures like that I finally figured out it was a spider on a web about 10 ft from the camera.
One thing I never figured out was I once had a setup where I would get a limb full of leaves right in front of the lens on more than half of the pictures. There was nothing nearby that could have caused this, even with the wind blowing, but every week I had more pictures with that limb in them.