They do?

Just a guess: The outer skin is splitting?

Yes I have noticed that. I think it is air, mine seem to bubble a bit.

popi reread my initial comments. - no bubbles so can't be air.

tom

Well I've got bubbles in mine ! My water is bubbling a bit.

Mine click and bubble slightly too, especially when I start to cook them. I got curious enough to park myself in front of the stove one afternoon while they were heating, and when the chickpeas on the top clicked, I could often see a slight movement and a tiny bubble rising to the surface of the water.

I never knew this until last week. When I lived in the uk I never heard them in my kitchen when I was in another room. But in my flat here in Barcelona the kitchen is near the bedroom and I woke in the night thinking we had mice! I didn't know where the noise was coming from until I tiptoed in the dark towards the kitchen worktop, there I found the source of the clicking

It's winter here and quite cold so after a few hours of soaking I added some warm water. The clicking started continuously. A few times a second. Zero bubbles. Zero movement. I can only imagine that it must be related to a movement between the skin and the bean.

And more likely the two halves separating.