Can I use small animal aspen

[beardless]

I have not seen it mold. As far as it getting in their mouth I have not had a problem with it. If I notice a decent size I usually try to pull it out while they are eating.

I have not seen it mould either, but yes unless you pull it out it can be an issue, like giant splinters, a young/shy snake wont like you poking in it's mouth pulling out substrate whilst feeding, and could leave the prey.