All the kids nap together. They CIO and learn they need to sleep/be quiet until 3 pm. On occasion when I first started I used to get them up early if they woke (but never more then 15 mins) but quickly learned that this became their new waking time. So I leave them till 3 and they are usually pretty quiet until 3.

The kids on cots can have books to read during nap time. With the exception of a new 3 yo (who reads/twiddles her thumbs in her cot for the 2.5 hrs), they all sleep.