Hi, I'm just wondering whether it's normal for your moles to go fully numb?

When I was younger a mole on my chest went numb to the point where I managed to pick a large chunk of it off without realising and now it looks like a 'C'.

This has happened to the same mole twice since that occasion, again picking off another piece without realising. It's also happened once to a mole on the back of my neck, which I picked fully off. Right now I have a mole on the left side of my neck which has gone numb, and I keep accidently picking at it in my sleep and when I'm sat down without thinking. I'm just wondering if this is normal?

Also, when they go numb, the mole itself goes really stretchy and almost loose, which makes it really easy to pick off. Whenever I've tried picking at my other moles to compare it's always stung way too much but when one of my moles goes numb it's genuinely as though it isn't attached to my body.

Please give me any advice on this as its worrying me a bit. Thank you!