their tired

An hour ago we asked our daughters to go to bed to sleep, but right now they are still awake. It is nine thirty in the evening now but still they never go to sleep. Few minutes ago Beth was here in the kitchen, she said she wants to sing the dog a song. I told her she can sing her tomorrow and our dog wants her to sleep. She cried and I felt bad. She really loves our dog but I want her to go to bed. They did not take a nap today and both of them were so tired already. I cannot understand of why the kids do not like to go to sleep even their sleepy