I don't believe that there is such a thing as 'bad behaviour' at that age, as frustrating as night wake ups are. My DD had periods when she would wake in the middle of the night for no apparent reason and be wide awake. If she didn't fall back to sleep almost as soon as I picked her up I knew she was going to be awake. Generally she would be awake for 2 hours and then just naturally go into a new sleep cycle. But oh my goodness the first couple of times she did it when I spent 2 hours trying to get her back to sleep were maddening. I would think she was asleep because she was so still but as soon as I tried to get her in the cot all hell broke loose. After that first time I just lay her in bed with me in the dark and knew she would eventually get back to sleep.
If its not teeth, and panadol or nurofen don't help, it may be something like we went through.