What causes high pitch noise in kitchen if it isn't electrical

Could be dozens of things...

Do you want to tell us something about this noise? Is it there all the time? If not, describe how often (& time of day) and for how long it appears.

When it's there, is it constant volume and pitch? Can you estimate the pitch (frequency)?

As you move around the kitchen, can you locate a spot where it's loudest? What is that near?

How do you know it's not electrical?

Daniel