Head banging -10 months

[Rental101]

My 10 month old has started to bang his head deliberately on his cot/ other items He now has some bruises on his head . Is this behaviour normal ? It’s hard to get him to stop it , I have to move him away.

Ps his development is normal is other ways , I just find the head banging strange .

Sometimes they do it through frustration when they understand more but aren't really able to communicate. Do you think that this is what might be going on?

Hi OP my son did and still does this and I got quite worried at first but I read about it and it's a way of them soothing themselves to sleep or back to sleep.