Vocalising

 Adult water voles

 Dead mole by the path

Juvenile water voles

It's rare to hear water voles vocalising, in my experience, but when they do it seems to be as a threat or protest towards another vole. The two in the top photo were apparently matched in size and age, but the one holding the apple was piping at the other to back off, which it did. I've heard an adult pipe at a baby to get out of the way, too. But they don't waste time squeaking about predators - they just vanish under water or down a burrow.