twin sleep trauma

Hi guys
untill recently my twins have been awesome to get to sleep they are 3 now and share a room they have got big kid beds but all of a sudden they refuse to go to sleep they have almost stopped sleeping during the day but it doesent seem to make much a difference they muck around talking and laughing and getting into each others beds and comming out of their room the only time they go to bed well is when i have totally wiped them out during the day i have started putting one of them in the spare room till they have nodded off they go straight to sleep when apart
I normally dont mind them mucking around a litte but this is going on till 9pm some nights which makes for grumpy twin mornings which we all know ruins your whole day.
So i want to know how do you all deal with it? is it time to put them in seperate rooms? or is this just another passing fase