Tired......

how can a mom get less than 6 hours of sleep and be able to function, albeit not very well, throughout the day???????nicholas is cutting his canine teeth and has been a crankass since saturday....he woke up last night and when i put him in the bunkbed with me he tossed and turned and slapped me in the face and poke his fingers up my nose and in my mouth....he was a general pain in the butt...now he is sleeping in our bed with daddy and i am exhausted....he would probably sleep for another 3 hours if i let him...