I have twin boys who are 6 years old and in year 1. Last year they loved school, so much so that they cried on snow days as they wanted to go in.
The beginning of year one was okay but gradually they have both begun to dislike school. I understand that year one is more work than play, unlike reception, and when DS1 was this age I could see why he would moan about school. However, I knew he just didn't want to do the work and now at 14, he is still a lazy little fecker 
Things seem a bit different with DS 2 & 3. DS3 is quite a nervous child, DS2 less so but still a little cautious. They both work hard and always try to do their best. However, when I pick DS3 up, he always looks like a rabbit caught in headlights. He never looks comfortable at school and always seems a bit on edge. I helped out on a school trip recently and he was like this the whole time. When I commented to the teacher, she said he is always like this. 
.
The funny thing is, they both do a lot of clubs etc and although they have been nervous starters, they have both relaxed quickly and I have not seen this nervouness in DS3 at any of these clubs.
DS3 has also started, on occasion, to wet himself. Not at school but on the way home and sometimes at the weekend. He wouldn never do this at school as he would be mortified.
They both now say they hate school and it is boring. DS 2 says the work is for babies and too easy, even though they both seem pretty average and although in top sets at the moment (I think) they are certainly not flying ahead of the rest of the pupils.
They have both made some lovely friends and are in separate classes. But there is a lot of bad behaviour going on and it is a large year group - 3 classes of 30. The other day they were both having a moan about school, on the way home in fact, and I commented 'what can we do about it then?'. DS3 replied 'move schools'
This shocked me as we have never discussed this, although one of their pre school friends goes to a different school so they know there are other options.
My problem is I find it hard to look at this objectively as we removed DS 1 from the partner junior school, due to lots of issues. WE agonised over where to send the boys but decided this would suit them, even though it did not suit DS1. Now I am worried we made the wrong decision, especially after a not great ofsted.
They also don't seem to be making as much progress as they did in reception, although I may be expecting to much as they obviously learnt lots of new things in reception and they are just building on that now. However a lot of their friends are now over taking them on reading levels (I know not the be-all and end-all) and I am worried they're not making progress and are unhappy.
So my rather long winded question is - how much of this is 'normal' for year 1? Something just doesn't seem 'right' and I can't put my figer on it.