Nice sentence — it is already correct! Here’s a simple, step-by-step explanation so you can see why:
- Subject–verb agreement: "Wolves" is plural, so the verbs "don’t" and "howl" match. (We would not say "Wolves doesn't.")
- Contraction: "Don't" is short for "do not" and is fine to use here.
- Meaning: "Their messages to one another" is clear. You can also say "to each other" if you like — both are correct.
- Punctuation: Using two short sentences is okay. You can also join them into one smoother sentence if you prefer.
Original (correct): Wolves don't use phones. They howl their messages to one another.
Smoother option: Wolves don't use phones. They howl to send messages to one another.
Try writing your own sentence about an animal that communicates without phones — I can check it for you!