It is important to change any provided water source daily. Even with the sipper bottles, as they may look full but can be blocked by air bubbles or may leak if the fittings are old. Sometimes wood shavings can get caught in them as well. Accidental water deprivation is, unfortunately, common and care must be taken to avoid it. My hamsters seem to sleep all day and then exercise on their wheel late at night.
Hamsters are nocturnal by nature.
Touching a hamster's back with a finger when she is sleeping will usually startle her and cause her to bite or act threatened. However, if they are woken gently and scooped up with two hands they usually don't bite. They can then be handled and played with. Remember, however, that hamsters are easily excited and may jump from hands if not held carefully. Also, keeping the lights low in the day may help.