13mo biting and now severe tantrums. Normal?

[Tuliptastic]

This is my first post and I'm sorry but it's a bit long!
13mo DD is normally a very happy and charming baby, but has started biting other babies at nursery in the last 2 wks. It's every day and this week she tried to bite 7 times in one day. I'm obviously mortified, but really am at a loss how to stop it. On the rare occasion that she bites at home we hold a hand up and say no, firmly. Then I gently purse her lips together for a couple of seconds and say no biting.

She doesn't do it out of malice, nursery think she gets overexcited and doesn't know how to express herself (she's always been a bit of an arm flapper)! She also has all her molars coming through at the same time, which probably isn't helping.

This was bad enough but today she had a HUGE tantrum at home (she was super tired just before bed) and bit herself (hard), cried and then did it again! During the same tantrum she also headbutted the wooden floor, twice (deliberately) and during bathtime she flipped herself onto her front and dunked her face in the water. It was like she was water boarding herself!

I know she was tired and I really tried to get her ready for bed as quickly as possible so she could sleep, but this doesn't seem like normal behaviour to me! Does anyone else's baby behave like this or should I be concerned? Also if anyone has advice about the biting I would be hugely grateful.

Thanks.

Very normal. My DS is also 13 months and the same. He's only bitten me and his sister so far though. He also head butts the floor when he's cross. And tonight he did it in the bath too! Which made him crosser...

He's such a sunny little boy most of the time. I imagine molars may be on the way - he had his first 8 teeth really early, but nothing for ages now. But the biting is out of frustration and temper, certainly. He uses lots of signs and words, so I can usually understand what he wants. However, I can't change the laws of physics which are what he is usually cross about...

I put my finger in front of his mouth and say 'no bite', and he usually shakes his head and laughs...

Not sure that's getting me anywhere, tbh!

Thanks for the reply, I'm so relieved that it's not just DD doing this!
I agree, it's so hard trying to stop the biting when they can't understand what you're saying, my efforts seem so fruitless most of the time. I just hope it stops at nursery soon, it's getting embarrassing and I feel bad for the babies she's biting.