[2020] small block to stop dogs coming in?

I mean, there's metal bars; but it'll obstruct shooting slightly. Alternatively concrete arrow slots. There IS a concrete half block too, though. And a concrete plate.

Craft a wet concrete block, hold it in hand, hold R/your reload key and select the shape menu- proceed to examine all the shapes.

Yeah, we all run into this problem of how to make the best opening in a wall from which to shoot. Though the arrow slit shape is specifically designed for this purpose, there are lots of options to get different sight lines, including ones that span multiple blocks. I've tried all sorts of shapes, and I've seen even more possibilities in others' videos. It's fun to experiment!