3 year old grandson excluded from nursery

Hello,

My three year old grandson has just been excluded from nursery.  He bit another child and then tried to bite nursery assistant as she was trying to change his nappy.  This was the first time we had been informed of any problematic behaviour.  I did ask the nursery lead 6 months ago how he was settling, and she said he did not really interact with others, but otherwise seemed quite happy there.

His Mum, my daughter has ADHD, but never wanted to continue taking medication for this following leaving school.

I had previously noticed that he used to twirl one way whilst his eyes were facing a different direction.  He also likes stacking or lining up bricks and other toys, he sometimes rocks, his speech is slower than others his age, and he does not really like to make eye contact and he will only accept a cuddle when he has hurt himself. 

Other than the above, he seems to be a happy child who likes playing with his toys and will happily watch television for a while.  He does not like to be read to, will throw or tear books, and will not let us play with his toys.  Otherwise his interactions with us are ok.