What do you call a small gap that allows you to see through something?

Question

Is there a word for it? I am thinking of things like a keyhole or a small gap in a bush. I am not sure if there's a name for it, but it would really help me out if you could find a word for it.

For example:

The hunter who hid himself in a small bush saw through a ___ a deer sleeping near a tree.

Answer 1

You are already using the simplest general word "gap". In this case it would be a "gap in the foliage". I'd probably phrase it as

... saw a deer sleeping by a tree through a gap in the foliage.

_{Do deer sleep? I've never seen a sleeping deer.}