I am a night owl and like to stay up late!!! Most of the time i stay up till 4 or 5 am.
i am the opposite, early bed early rise
I've never heard of an early bird, but night owls are called B-people in Scandinavia.  Hootie Hoot.
that's funny, a new way of describing it.
Yes it is and I am starting to believe that i may have  delayed sleep-phase disorder, a difficulty waking up and going to sleep at the "correct" times.  LOL You day people always think you are right about everything. LOL
whats that called your inner clock
Oh sure, blame it on my Circadian rhythm .  All animals have one, but that doesn't explain why some animals are up during the day and others are up at night.
early to bed, early to rise, makes a man wealthy and wise
Sleep inversion
Sleep inversion or sleep-wake inversion is a reversal of sleeping tendencies. Individuals experiencing sleep-wake inversion exchange diurnal habits for nocturnal habits, meaning they are active at night and sleep during the day. Sleep-wake inversion, when involuntary, can be a sign of a serious disorder.
Symptoms.
Individuals with the delayed sleep phase type of the disorder exhibit habitually late sleep hours and an inability to change their sleeping schedule consistently. They often show sleepiness during the desired wake period of their days
Night owl (person)
A night owl, evening person or simply owl, is a person who tends to stay up until late at night, or the early hours of the morning. Night owls who are involuntarily unable to fall asleep for several hours after a normal time may have delayed sleep phase syndrome. 
The opposite of a night owl is an early bird – a lark as opposed to an owl – which is someone who tends to begin sleeping at a time that is considered early and also wakes early.