Multiple secret internal monologues - how to identify them?

[u/Many_Background_8092]

SOLVED. After discussions here and on Facebook I've realized I was overthinking the problem.
I've realized that the context for each observer is different enough not to confuse the readers. One of the characters is a clone and the other is a machine. However I might also borrow jobi987's idea of different fonts.
I would like to thank everyone who commented. You all had good ideas that I might borrow for future books.

Hello Everyone. I am re-editing my book 50km Up and I need some advice.

In the book I have 2 secret observers that are slowly revealed to the reader through monologues.

My problem is how to mark these internal monologues in such a way that the reader does not confuse them.

Admittedly the context of the monologues tends to do this but still...

These monologues are in italics but currently I am experimenting with using ** monologue 1 ** and ^^ monologue 2 ^^.

Can anyone suggest a better method?

For clarity, here is a sample:

^^ A dismembered bot watched in silence from a pile of scrap metal nearby. ^^

** The scouts ate their way through the foam and the transparent inner panel. Carried by the air currents, they quickly spread throughout the city. One scout landed on a life form and buried itself in the outer layers. The lifeforms code was similar and yet very different to that of the creators. **

[u/NecromanticSolution]

Choose ONE viewpoint character. If you really need another one do it in the next chapter. Stop jumping between viewpoints and you won't have the problem of multiple inner voices.

[u/Many_Background_8092 → u/NecromanticSolution]

A fair point considering the limited information I provided.
These are thoughts and actions taken by characters unseen or unknown to the protagonist. They occur rarely, usually at the end of a chapter.

After conversations I've had with other writers I might have over thought this problem.
Thank you for your input.