To help you figure out what's making the noise in your trees, I need some more information:
* Where are you located? Different bugs live in different parts of the world.
* What kind of trees are they? Some bugs prefer certain types of trees.
* What does the clicking sound like? Is it loud or soft? Fast or slow?
* What time of day do you hear it? Some insects are active during the day, while others are nocturnal.
Once I have this information, I can try to help you identify the bug.
You can also try searching online for "clicking bug" or "insect clicking sound" and see if any of the results match what you're hearing.